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(Message started by: omar on Dec 27^th, 2004, 2:04am)

Title: Postal Tournament
Post by omar on Dec 27^th, 2004, 2:04am

There seems to be quite a bit of interest in having a postal tournament. I've discussed this with several people in the chat room and we tossed around some ideas. I've written up some pages for it. Some things I've written are a little different than what was discussed in the chat room. Would like to get some discussion on the details of this before we go forward with it.

http://arimaa.com/arimaa/tourn/postal/2005/

Omar

Title: Re: Postal Tournament
Post by Fritzlein on Dec 27^th, 2004, 12:39pm

Omar,

This looks fantastic. I think the time control of 24 hours per move and 5 days in reserve is fine, although I can see an argument for a 10 day maximum reserve. (You wouldn't have to increase the starting reserve, so it wouldn't lengthen the tournament any to increase the maximum reserve.)

The 180 day cutoff is fine. That insures a minimum of 85 moves, even counting the initial reserve. There has never yet been a human vs. human game lasting 85 moves. If this happens to be the first time, we'll know that future postal tournaments, but I don't expect it to happen. Postal chess games don't necessarily go more moves than regular chess games, and until proven otherwise we can assume the same for postal Arimaa.

I like having a $10 entry fee. One of my fears was that people would sign up without taking it at all seriously, and then abandon all their games after a week or two. It is still possible that this will happen, but less likely when there's an entry fee.

Here's a suggestion for the prize money to take commitment one notch higher: rather than giving it back for first, second, and third, return it for committed play. If you win a game you get 100 points and if you lose you get the number of moves the game lasted (to a maximum of 90). When it is over, the entry money is given back proportional to the points accumulated. My idea is that an entry fee is mostly to ensure commitment, not to create a prize fund for top players to win. Giving back the entry fee in the way I suggest will encourage people to fight it out, and not resign or abandon games.

Anyway, where do I sign up?

P.S. This reminds me to ask for a feature for the server. When you click on "Current Games" it would be nice if each game had the move number and player to move displayed by it, e.g. "S23" to indicate that it is Silver's turn to move on the 23rd move. That way when I log in to check on my postal games, I won't have to open each one to see whether my opponent has moved or not.

Title: Re: Postal Tournament
Post by omar on Dec 27^th, 2004, 4:58pm

Thanks for the feedback Karl. I really like the suggestion for giving back the entry fee based on committed play. Lets see what others think.

I'll add the sign up page once we finalize the rules.

I will be changing the 'Current Games' so that it only shows interactive games and there will be a seperate page for postal games. I will add the move status to the postal games.

I can also make the max reserve time longer. Lets see what others think.

Title: Re: Postal Tournament
Post by MrBrain on Dec 27^th, 2004, 5:52pm

I think 7 days reserve would be the most that anyone will need. For me, 7 would be better than 5. I don't think starting with the maximum reserve is necessary.

As far as the 180 day limit, I like it. But rather than looking at it as an 85-move-ish limit, let's use the postal tournament to implement the idea of not using the scoring function to decide the game, but rather who's used less time. Then you won't really limit the number of moves at all, but rather how long you can continue to think about each move in a very long game.

Title: Re: Postal Tournament
Post by jdb on Dec 27^th, 2004, 6:36pm

I suggest the max reserve time be somewhere in the 7-10 day range. The tourny could take 6 months. This would give enough time for someone to take a break. (ie vacation or business trip)

I like the idea of scoring based on moves. How about rewarding a quicker win. Say, the winner gets 200 pts -number of moves. The loser gets a point for each move. If the game is not over when the time limit is elapsed, BOTH players lose. For scoring purposes, the move limit is capped at 90. (but the game can of course continue!)

Title: Re: Postal Tournament
Post by Fritzlein on Dec 27^th, 2004, 10:37pm

I'm not sure how much I like the idea of rewarding quicker wins more than slower wins if the scoring system is primarily to reward committed play. When there was a prediction contest going on (with money on the line) it made sense to reward quick wins, so that the players would have a disincentive to mess with the prediction contest. In the World Championship, if I had gotten the same number of prediction points for winning quickly or slowly, I might have purposely dragged out a win to ninety moves just to stop other people from getting so many prediction points.

In the postal tourney, where there is no prediction contest we have to protect the integrity of, I'm not sure that we need to reward quicker wins more than slower ones. Besides, if a thirty-move win would score 170 to 30, it gives the losing player pretty poor compensation for being committed. I say 100 to 30 is quite enough of a swing, and maybe too much. On second thought I might prefer giving the winner a flat 75 and the loser the number of moves, capped at 65.

As for Mr. Brain's suggestion of deciding a time-cutoff game on the basis of who used less total time, I don't like it much, but I favor it over the present scoring system. In fact, I'm in favor of almost all the proposed alternatives to the present scoring system. The criterion of using less total time might have the desirable effect of bringing the game to a conclusion on the board before the 180 days are over: if it looks like the time cutoff might be in play, then the players will each try to move faster, and by the same token if one player is consistently moving in less than a day to get ahead on time early, that will mean that more than 90 moves get played in the 180 days, also tending to bring a conclusion on the board. The main disadvantage I see in the new rule compared to the present rule is that it requires extra programming on Omar's part to display total time used, whereas the wacky score function is good to go at present.

Title: Re: Postal Tournament
Post by Paul on Dec 28^th, 2004, 2:13am

I don't really like the idea of rewarding long games, for two reasons :
- using Fritzlein suggestion, one can imagine winning the tournament with 10 losses in 65+ moves. 650 points will not be easy to beat
- this method of scoring risks to conduct to very conservative and defensive games.

So I propose to keep things simple : 1 point for a win, and 1/2 for a draw.

Also, I propose that colours are determined to insure each player to have an egal number of time silver and gold. I don't see the point of letting the lowest rated player choose his colour.

For the prize money, do we really need one ? Why not simply ask for an entry fee refundable if all games are played ? I seriously doubt any player will participate for the prize.

Paul

Title: Re: Postal Tournament
Post by MrBrain on Dec 28^th, 2004, 9:37am

I think people are really missing the point of deciding a game by who's used less time. All it really does is to put a limit on the total time you can think for a game. This solves all the problems that we had for the last championship, and frankly the main problem with the arimaa time controls.

I complain, "Why can't we have 2 minutes a move?". Answer: "Because we need to have people be able to fit the game into their schedule." If we did 2 minutes a move, then to accomodate a really long game (say 100 moves) we need to allocate 7 hours. So why can't we have 2 minutes a move with a 5 hour limitation? Reason: The awful scoring function will kick in.

Now imagine that the game is decided on who uses less time. What is really the end result? It is that nobody will dare use more than 2.5 hours (150 minutes) for all moves, regardless of how long the game goes. In effect, we preserve the 2 minutes per move early in the game, and then when the most fantastic game of arimaa ever happens (goes 85 moves perhaps), the players just start moving quicker toward the end, and we have a real winner. In the rare case that someone continues to use 2 minutes per move, they will effectively lose on time (because they used more than 150 minutes).

This really is the solution to our problems with arguing about fast/slow, fit-into-schedule/can't-fit-it-in. You can play at a reasonable pace (2 minutes for championship, 1 day for correspondence), but still have a way to end the game reasonably. Ending a game because BOTH players have used a certain amount of time is really very bad. That's why chess clocks exist. Each player has a certain amount of time. You don't just have one big clock.

Title: Re: Postal Tournament
Post by MrBrain on Dec 28^th, 2004, 9:47am

Again, I emphasize... please think about what would happen really if we had the least-time decision mechanism. Would the game really end on time? Go through a game in your mind and figure out how people would really play. If I'm playing with this new decision mechanism, I know that I should not go over 150 minutes total in a 5-hour-limit game. The game is getting up to 60 moves. We've used 3 hours, 48 minutes total. I've used 1 hour and 52 minutes. I know that I should not use more than 38 minutes for my remaining moves, otherwise, I will be in danger of losing the game by having used more time than my opponent. Solution: Move a little quicker. Easy!

So would the game really end at 5 hours? Very unlikely. What is more likely to happen is that the people will speed up their play (or will have played faster earlier in the game) to avoid any chance of running into the 5 hours.

Title: Re: Postal Tournament
Post by MrBrain on Dec 28^th, 2004, 9:53am

Now as for the postal tournament, I believe that Omar said at one point that the amount of time used/left is recorded somewhere in the game log for each game. Is this correct? If so, I don't think it's necessary for it to be displayed since, as people have already pointed out, it's very unlikely that the 180 day limit will come into play. If someone does happen to get close to 180 days, one could simply access, or ask Omar to access, the game log and calculate the total amount of time used for each player thus far. Also, it may be likely that this feature will be in some sort of interface by the end of such a game (more than a half year away!)

Title: Re: Postal Tournament
Post by Fritzlein on Dec 28^th, 2004, 11:18am

Paul is right. The simplest thing is to keep winning the tournament totally separate from the prize money. Winning should be based on 1 point for a win and 0.5 points for a draw. Then we can refund the entry fee to people who don't abandon their games. That's what the entry fees are for, after all.

The reason I wanted to reward number of moves, though, is that it is possible to abandon games without resigning or losing on time. If I wanted to quit after ten moves, but I still wanted my prize money back, I could just start suiciding my pieces, or even dragging the opposing rabbits to the goal.

We could still use the regular formula for determining the tournament winner, and my formula for giving out the prize money. It would be very unlikely (although mathematically possible) for the tournament winner to not get the most money. It is more of a concern to me that someone might purposely choose a move with no chance of winning and a good chance of losing slowly over a move with some chance of winning and a good chance of losing quickly. That would be too bad; I see it as a tradeoff: in order to discourage suiciding we risk encouraging poor play in some sense.

Title: Re: Postal Tournament
Post by Fritzlein on Dec 28^th, 2004, 12:02pm

on 12/28/04 at 09:37:26, MrBrain wrote:

I do agree that this time control solves many of our problems with the Arimaa time control, but I'm still slightly leery of adopting it for interactive games.

The reason I'm in favor of your suggestion for the postal tournament is that
a) It's better than the current scoring function
b) 85 moves is long enough that almost all games will end naturally without the rule coming into play at all
c) 24 hours per move is long enough that a "time scramble" may mean trying to move in half a day each time rather than in a full day.

But I maintain my distaste for sudden death time controls in interactive games. I like to take away a player's ability to leave himself, say, one minute for all remaining moves.

The proposed time cutoff isn't so bad because it is only half-way sudden death. The players can't dawdle at the beginning: they have to move at basically the time-per-move pace, because the reserve is less than the sudden death control. I don't mind letting players move at faster than the time-per-move pace if they want to, even when they have a full reserve. But the remaining drawback is that players may be unaware of the time pressure from the time cutoff in a long game, and shoot themselves in the foot that way. To avoid that scenario, I personally would prefer time controls that got faster gradually but always left a certain time (say minimum 30 seconds) per move.

Title: Re: Postal Tournament
Post by MrBrain on Dec 28^th, 2004, 12:36pm

on 12/28/04 at 12:02:42, Fritzlein wrote:

The proposed time cutoff isn't so bad because it is only half-way sudden death. The players can't dawdle at the beginning: they have to move at basically the time-per-move pace, because the reserve is less than the sudden death control. I don't mind letting players move at faster than the time-per-move pace if they want to, even when they have a full reserve. But the remaining drawback is that players may be unaware of the time pressure from the time cutoff in a long game, and shoot themselves in the foot that way. To avoid that scenario, I personally would prefer time controls that got faster gradually but always left a certain time (say minimum 30 seconds) per move.

Yes, that would be better, but that would require a major modification to the arimaa time controls. My idea (really Omar's idea) is easy to implement (we don't need to do it right now), and practically will have almost no effect on arimaa games (as someone noted, the longest-ever game between humans was 75 moves). It's really a correction to what I believe was an error originally, which is having a deadline that's for both players, instead of each player individually.

Title: Re: Postal Tournament
Post by omar on Dec 31^st, 2004, 12:57am

Brian I think I finally see your point about changing the meaning of the game time limit. The purpose of the game time limit parameter (G) was to accomodate situations in which a game must be completed within a certian amount of time. It can still acheive this purpose if we define it to mean the maximum time that can be used by each player for the whole game. So if a game should be finished in 4 hours we currently set G=4, but with the new definition we would just set G=2; meaning that each player can use a maximum of 2 hours for the whole game. The advantage of this is that it eliminates the need for an alternate method such as a score to determine the outcome of the game. I will make this change after the computer championship and challenge match events are over.

For the postal tournament I think we can increase the game limit parameter to 300 days. I don't think any game will ever hit that limit with a 1 day per move pace. The game would have to be about 150 moves before it hits that limit. So I don't think we need to worry about a game being decided by score. I think a much bigger concern is a game being decided by time running out. So I don't mind having a much larger starting reserve and reserve limit to try and prevent that from happening. So I think maybe even having a reserve and max reserve limit of 14 days might be OK. As JDB mentioned it would give people a chance to go on vacation and not worry about losing the game on time. So the new proposed time control is:

1d/14d/100/14d/300d

Paul suggested fixing the color assignment so that everyone plays an equal number of games with each color instead of letting the lower rated player select the color. I think we can accomodate this. How about fixing it so that against the first opponent on your left (in the ring) you play as gold, the second one you play as siver and so on alternating. This fixes the colors for the player on your right. This can also be applied for the round robin case by creating a similar ring (as described in the tournament rules). But in the case when there are an even number of players and you are playing the opponent on the opposite side of the ring, the lower rated player plays gold.

For determining the winners we will use the simple 1 point for win and 0.5 point for draw. But I still like Fritzlein's idea of putting the registration fees into a shared prize pool and redistributing it after the tournament based on the performance formula he suggested. I think it adds a little more fun to the tournament :-)

Title: Re: Postal Tournament
Post by MrBrain on Dec 31^st, 2004, 10:06am

Yes, Omar, that was my initial proposal to change (or enhance) the arimaa time controls. But after thinking about it, your suggestion of simply changing the winner-deciding mechanism is actually sufficient. If I know there's a 4-hour limit for both players total, I'll make sure to make all my moves in under 2 hours. But even if I don't, with the current 2-person-total limit, I may be able to win the game by goal before total time reaches 4 hours. But again, either way is very close to the same, so I'm fine with either one.

I like the proposed time control. That should be sufficient.

Now, here's another question: How do we prevent a player from "parroting" another player's moves in order to win 1 of 2 tough games? In other words, how can we prevent player A from relaying opponent B's moves onto the board against opponent C? We should have some rule against this, but how?

Title: Re: Postal Tournament
Post by Fritzlein on Dec 31^st, 2004, 9:44pm

Omar, I'm glad that you are changing it so that everyone has half gold and half silver. Also I approve of the maximum reserve being 14 days. I don't entirely like the 14 day starting reserve, though, and would suggest 7 days instead, although it's not a big difference and I don't care a great deal. My feeling is just that if anyone signs up for the tournament and quits before the first move, I think a week is long enough to wait for them. To get a two-week break later, you have to earn it by punctuality between now and then.

Mr. Brain, I had also worried about someone deciding to act as a conduit between two other players, in order to be assured of at least one of the two points. My conclusion was that as a player I don't mind so much, because I get an interesting game no matter who I am really playing. As a tournament director, I would be more concerned, but maybe because of the time controls it wouldn't work well for the in between player. It would always take the intermediary longer to make a move than the player who actually thought of it, so gradually the imitating player would deplete his reserve and run out of time, unless both of the other two players were consistently moving in less than a day with a full reserve. (This is incidentally another minor reason not to start folks off with a full reserve. If I notice that my moves are being relayed, I can slow down the pace of my moves until the copier runs out of reserve and has to be original.)

I'm psyched for the tournament to begin!

Title: Re: Postal Tournament
Post by omar on Jan 4^th, 2005, 9:56pm

I was looking at the recent games and noticed some of the 15 second per move games against bot_Speedy that reached the game time limit and were determined by score. I think the scroing function did justice in those games and gave the game to the player who I would also consider to be winning.

I plan to add the following to the time control definition
for the G parameter:

* If the number ends with 'k' then the time per move is linearly decreased with each move until it get down to 30 sec per move by the move number given by G. For example, if G=60i and M=90s then after each move the M parameter is reduced by one second. After M gets down to 30 it does not decrease any further.
* If the number ends with 'b' then the first player to use up this much total time in all the moves loses.
* If the number ends with 'x' then after the game time limit is reached the player who has used less total time in all the moves wins.

So the current definition of determining the outcome by score will also be there.

Regarding the move imitating problem. I will be sure to mention in the tournament rules that this is prohibited.

Title: Re: Postal Tournament
Post by omar on Jan 5^th, 2005, 6:12pm

I've updated the postal tournament pages. Please have a look.

http://arimaa.com/arimaa/tourn/postal/2005/

I changed the distribution of the shared prize a little
from what we discussed. Also increased the reg fee a
little since everyone will get at least some of it back.

Omar

Title: Re: Postal Tournament
Post by Fritzlein on Jan 5^th, 2005, 9:22pm

The only thing I don't like about it is that I have to wait until January 23 to start. :-)

A few small points:

* A strict reading of the rules would say that losing by immobilization is worth -50 points, since it is losing "any other way", but I imagine you want it to be +25 points, just like losing by goal.

* I hope that nobody will make bad moves intentionally instead of resigning. It is possible that , since we aren't reward extending the game in any way, someone who wanted to resign would pull an enemy rabbit to the goal. The way the rewards are set up might tempt someone to behave in this manner, because there is no per-move reward, but at some point you just have to rely on people to be sportsmanlike.

Title: Re: Postal Tournament
Post by 99of9 on Jan 6^th, 2005, 5:30am

The following will seem quite negativve - apologies. I like the tournament as a whole, but I think there are a few things that should be cleared up before we begin.

* Losing by repetition should be explicitly mentioned too - is this a bad way or good way to lose?

* I thought we had a great way to incentivize playing hard in the prediction contests. Points for long games if you lose, points for short games if you win. Why did you decide not to use that system Omar?

* I'm afraid that Gnobot will not be able to enter this comp, because I will be moving country during the tournament and will not have fixed hardware to run it on.

* I think the webcam clause is a bit silly in a postal tournament. Unless Omar enjoys watching Big Brother :-). If somebody really wants to cheat in a correspondence tourney, they'll be able to no matter what rules you put in place. The webcam rule is particularly ineffectual though, because any cheating I do could be in a different room or at a different time.

* I think the "ring" system of deciding opponents is unfair. It gives massive advantage to the top seed compared to the number 6 seed. Say there are 100 entrants (obviously there won't be... but just for the example, say there are):

Top seed plays #2, #3, #4, #5, #6, #100, #99, #98, #97, #96
6th seed plays #1, #2, #3, #4, #5, #7, #8, #9, #10, #11

I haven't thought about it for long, but I'd say that even deciding opponents randomly would be better than this.

Title: Re: Postal Tournament
Post by omar on Jan 6^th, 2005, 6:36pm

Thanks for the feedback guys. I've updated the 'Prize Distribution Rules'. I think it now reflects the original intention much better.

I didn't notice the web-cam rule when I cut and pasted the paragraph from another page. I've taken that silly line out. Thanks for mentioning it.

Toby, your calclulations about who plays who in the ring are different from mine. Here is what I get:

First order the players by ratings (assume player 1 is highest rated and 100 is lowest rated). Then order the players like this:

1 3 5 7 ...... 97 99 100 98 ...... 8 6 4 2

Now form the ring with player 1 next to player 2. This means that player 1 plays: 2, 3, 4 ... 10, 11. And 100 plays 90 ... 99. Player 6 would play: 1, 2, 3, 4, 5, 8, 10, 12, 14, 16.

If you want I can run GnoBot on my server for you. It might not do as well since its only a P4 1.7G machine with lots of other processes running. But at least it will get to play.

Title: Re: Postal Tournament
Post by 99of9 on Jan 6^th, 2005, 7:23pm

Oh OK - I didn't understand how your ring was operating. Your method seems ok then.

Are you really happy to have 10 extra processes running on your computer?? I'll have a think about it - it might not be worth it anyway.

Title: Re: Postal Tournament
Post by Adanac on Jan 7^th, 2005, 8:34am

I really like all of the recent changes and clarifications to the tournament setup, especially since I now know that I can take my vacation time without worrying about forfeiting any games and I won't need to buy a webcam!

Now I just need to learn how to play this game well in the next few weeks.

Title: Re: Postal Tournament
Post by MrBrain on Jan 7^th, 2005, 11:40am

I would recommend putting a new link for the postal tournament in the main game room. Also, when is the deadline for sending the $20 entry fee?

Title: Re: Postal Tournament
Post by omar on Jan 7^th, 2005, 4:21pm

Toby. If I run GnoBot I was thinking of only letting it think for about 1 hour per game and one game at a time.

The registration dead line is Jan 23rd.

Omar

Title: Re: Postal Tournament
Post by Fritzlein on Jan 8^th, 2005, 8:27pm

I sent in my $20. Do you think we might actually get more than ten players? What a boost for Arimaa that would be! I was expecting maybe five or six players. Omar, I think it would encourage more people to sign up if you post to this thread (and keep updating by edit) a list of everyone who has already paid up. Or you could automate it and have it be somewhere on the tournament page. Some people who are wavering might jump on the bandwagon if they see that everyone else is doing it too.

Adanac, you're getting good too fast already. No need to pick up the pace. In fact, playing against you will be no bargain for anyone else's rating. The effect of these games on our ratings will be based on the ratings we have at the start of the games, yet I'm sure by the end you will be several hundred points stronger, so those of us with established ratings will earn less than we deserve for beating you and lose more than we should for losing to you. >:( Oh, well, the tournament will be a blast, and to heck with the ratings. I'm going to deflate my rating sometime between now and tournament begin anyway by playing bot_lightning in rated mode.

Title: Re: Postal Tournament
Post by 99of9 on Jan 13^th, 2005, 11:14am

Omar, I see you've made a "postal games" link from the gameroom. Now that you've done that I suggest you cut them out of the "current games" list, because that is what's going to get clogged up once the Postal Tourney starts.

I don't think Gnobot should play. It doesn't get many extra ply even when playing for ages, and it's not very good in the first place, so I don't think it'll contribute anything useful.

I on the other hand have definitely signed up, it should be great fun. I think the games will produce some spectacular theory.

Title: Re: Postal Tournament
Post by 99of9 on Jan 13^th, 2005, 11:18am

on 01/08/05 at 20:27:46, Fritzlein wrote:

those of us with established ratings will earn less than we deserve for beating you and lose more than we should for losing to you.

You think you have an established rating eh Fritz?? I haven't seen much sign that it has ceased it's eternal skyrocket.

Title: Re: Postal Tournament
Post by Fritzlein on Jan 18^th, 2005, 2:45am

on 01/08/05 at 20:27:46, Fritzlein wrote:

The effect of these games on our ratings will be based on the ratings we have at the start of the games...

I take it back. Apparently even though the ratings from the start of the game are listed next to the game while it is being played, the ratings adjustments are based on what the ratings happen to be at the end of the game. Is that correct, Omar?

Title: Re: Postal Tournament
Post by 99of9 on Jan 22^nd, 2005, 4:43am

13 players!!!

That's great. It's a pity that it won't be an all-play-all round robin, but that would've just been too many games. I'm sure that whatever it is, it'll be fun, and it's great that so many are involved.

Title: Re: Postal Tournament
Post by omar on Jan 23^rd, 2005, 2:46pm

Yes, the rating is computed using the current rating at the end of the game; not the rating at the start of the game.

We are up to 15 players now.

Title: Re: Postal Tournament
Post by 99of9 on Jan 24^th, 2005, 3:23am

good luck all

Title: Re: Postal Tournament
Post by Fritzlein on Jan 24^th, 2005, 9:07am

Shouldn't the clock of the Gold player be started in each game where no moves have yet been made? I can understand having a short grace period, but the starting date of the tournament was publicized in advance, and already players have 1 day to move plus 14 days reserve time. It seems logical for the clocks to start ticking now for exactly the same reasons they will run throughout the rest of the game.

Title: Re: Postal Tournament
Post by 99of9 on Jan 24^th, 2005, 4:59pm

Love to have bomb fired up soon.

[edit: David, Omar just posted in the bot forum about how you have to configure this.]

Title: Re: Postal Tournament
Post by fotland on Jan 24^th, 2005, 7:05pm

I should have gotten the scripts installed and debugged last weekend, but I had a computer go deadline yesterday. I'll do it this evening after dinner.

I'm going to try to make it fully automated so bomb can think about 3 hours for each game.

Title: Re: Postal Tournament
Post by RonWeasley on Jan 24^th, 2005, 7:59pm

I didn't realize we were going to get howlers after every move.

I share my e-mail account with my twin brothers, Mum and Dad, little sister, and my git of a brother Percy. The flames are blocking the fireplace. Any way to stop e-mail notification?

Title: Re: Postal Tournament
Post by 99of9 on Jan 24^th, 2005, 8:03pm

Ron you could set up some rules in your mailbox to redirect all these messages to a separate folder. What mail client do you use?

Title: Re: Postal Tournament
Post by fotland on Jan 24^th, 2005, 9:58pm

Bomb is working now. It's automated, and will use 2 hours per move.

Title: Re: Postal Tournament
Post by fotland on Jan 25^th, 2005, 1:25am

In two hours it did 21 iterations, with a maximum depth of 29 steps. It won't look so deep in the middle game.

Title: Re: Postal Tournament
Post by 99of9 on Jan 25^th, 2005, 4:35am

Wow... we're in real trouble world! Make sure you concentrate hard in your bomb games!

Title: Re: Postal Tournament
Post by MrBrain on Jan 25^th, 2005, 8:07am

on 01/24/05 at 09:07:37, Fritzlein wrote:

Shouldn't the clock of the Gold player be started in each game where no moves have yet been made?

Yes, I agree completely. I have started the time on all of my gold games even though I won't have time to actually make any moves until later tonight.

Title: Re: Postal Tournament
Post by 99of9 on Jan 25^th, 2005, 9:54am

on 01/25/05 at 01:25:02, fotland wrote:

In two hours it did 21 iterations, with a maximum depth of 29 steps. It won't look so deep in the middle game.

Since I had the time to do it, I counted how deep I analysed one line of my last move against Paul. It got to a depth of 7 moves each (56 steps). But that was only one very slender variation... so chances are we will deviate within one or two moves. By the way Paul, if we follow all 14 moves... we end up equal but having exchanged a few pieces :-). I'll let you know when we deviate, and publish my analysis.

Title: Re: Postal Tournament
Post by fotland on Jan 25^th, 2005, 10:54am

So people will still look much deeper. I'm getting a branching factor of just over 2x time per additional step searched. So each additional Arimaa move takes 10 to 20 times longer to search. With this search algorithm, bomb will never search 56 steps in the middle game.

Title: Re: Postal Tournament
Post by 99of9 on Jan 25^th, 2005, 2:00pm

I doubt I'm ever likely to again. It was too much effort :-). In most 1 minute games I estimate that I routinely search a depth of 12, and along some lines 16, but nearly never more.

Title: Re: Postal Tournament
Post by RonWeasley on Jan 26^th, 2005, 8:07am

Thanx for the advice about e-mail, 99. I should have learned that as a second year, but classes were cancelled near the end of the term.

And I figure I look ahead about 6. Steps, that is. I bet by now you've figured that out.

Title: Re: Postal Tournament
Post by 99of9 on Jan 26^th, 2005, 10:24am

I think you underestimate yourself Ron. Arimaazilla searches 8, and you routinely beat it. When you rushed across on move 8w of our game to save your horse, you must've been seeing the horse getting killed at 14 ply, so instead you were willing to sacrifice your cat at 16 ply. So I'd say that in some lines you look to a depth of at least 16.

Title: Re: Postal Tournament
Post by RonWeasley on Jan 26^th, 2005, 1:45pm

OK, 8 then. And that's my final offer. :P

Title: Re: Postal Tournament
Post by RonWeasley on Jan 26^th, 2005, 4:18pm

On reflection, this brings up an interesting point. Most of the comments about bot strength have been about search depth. Aarima was designed, successfully I think, to be a difficult search problem due to the large number of nodes. My interest comes from the personal experience of not really seeing the game as a tree of steps.

When I see a brilliant chess move, or an aarima move (always made by somebody else), I see a sequence of tactical or strategic ideas. Examples: attack multiple areas, block access to a vulnerable area, pin the piece protecting the square needed en route to successful force projection around the king. This kind of human thinking doesn't always rely on plies.

I hope someday to create a bot that emphasizes this approach. It may look many plies in parts of the tree, but its evaluation should use these higher level concepts. I realize this may just be a shift of the cognitive load more to the static evaluation function. Perhaps I'm just proposing more detail there. However, my experience makes me expect that there is something more.

Unfortunately for aarima, I got involved with a new business this year. Group W is doing well! No time for bot_aardvark development anytime soon. Sorry I can't share this now.

As for my own play, I'm pretty bad at tactics. I don't see many possibilities before they're played. I'm better at seeing them AFTERWARDS. That element of surprise is rewarding. So I try to use the higher level concepts. Like in the game with 99of9, I saw losing a horse versus losing a cat and possibly losing a horse and dog for his camel. I didn't think farther. It was all based on proximity and control. For me it was about a 5-ply decision.

My hope is that a bot that thinks this way would be the new type of AI Omar had in mind when he started the challenge. Snape thinks this is all rubbish.

Title: Re: Postal Tournament
Post by 99of9 on Jan 26^th, 2005, 5:21pm

on 01/25/05 at 09:54:32, 99of9 wrote:

Ok here goes - I'm not sure anyone's interested in this analysis, but I said I'd write it down - so I will. We did indeed deviate after 12 steps.

6b Md3n ee3w Hb4n mb3n 7w Ef4w Md4n Ee4w Ed4w 7b ed3n Md5n ed4n hb7s (played up to here) 8w mb4s Ec4w Hb5e Ce1n 8b Hc5n ed5w ra7e dd8s 9w mb3e (x) Eb4s Eb3e Ec3e 9b ec5e ed5s Md6s (x) ef6e 10w Ed3w Ec3n Ec4n Md5e 10b ed4n Me5n ed5e dd7s 11w Ec5e dd6w Ed5n Me6n 11b ee5n cc7e dc6n rc8e 12w Ed6s Ed5e Ee5e Ef5e 12b ee6e Me7s ef6s Me6e (x) 13w hg4w Eg5s hf4s (x) Eg4w

Paul deviated onto a path that I had considered, but not to the same depth. You can probably see why I had to go to this depth for this line, because it is sharp the entire time, and all the biggest pieces are at risk. At the same time there are often only one or two decent choices at each move, so it's possible to go to such a depth.

Title: Re: Postal Tournament
Post by fotland on Jan 27^th, 2005, 12:59am

Some questions about bomb and the postal tournament. Right now I have it running in a script that tries each game in turn, and thinks two hours for each move. I haven't touched the computer its running on since Monday.

What will happen if the computer crashes or there is a power failure or I abort the script? It will be processing a "bot move" command at the time. Will it be able to redo that move later? I assume that the game is not affected, and the clock keeps running, and the bot can play the same move later.

I just realized that I can have it play much slower, since opponent time doesn't against it. It could probably meet the time control with 3 hours per move, since the average opponent takes a half day to move. I could do a more sophisticated script that plays first in the game with the least time left, rather than playing them in order.

I don't want to change the time limit, but if I did, would the rules allow it? It seems against the spirit of the rules at least.

Title: Re: Postal Tournament
Post by fotland on Jan 27^th, 2005, 1:08am

on 01/26/05 at 16:18:29, RonWeasley wrote:

When I see a brilliant chess move, or an aarima move (always made by somebody else), I see a sequence of tactical or strategic ideas. Examples: attack multiple areas, block access to a vulnerable area, pin the piece protecting the square needed en route to successful force projection around the king. This kind of human thinking doesn't always rely on plies.

I hope someday to create a bot that emphasizes this approach. It may look many plies in parts of the tree, but its evaluation should use these higher level concepts.

This is the way bomb works. The evaluation function sees the concepts you mention (hostages, frames, advanced rabbits with protection, elephant mobility, trap control, etc.)

It doesn't search to a fixed depth. Interesting sequences are searched more deeply. In the postal games it's only looking 8 steps on some sequences, looking 14 steps typically, and looking 25 steps in the more tactical lines.

As I improve bomb, I make the strategic parts of the evaluation more accurate, and the search more unbalanced.

David

Title: Re: Postal Tournament
Post by Paul on Jan 27^th, 2005, 4:35am

I've considered during a longtime playing mb4s Ec4w Hb5e Ce1n as 8th move.
It was probably better than taking the camel directly.

The interessing point here is that i've chosen my actual move (Ec4n mb4e mc4s Ec5s) because I'm playing Toby : I would have certainly choosen the other way against a weaker opponent.

Now I've a somewhat inferior game (Toby has the initiative), but also a more stable and flat game : with the camel exchange so soon in the game, a lot of tactical possibilities are gone.

I've played exactly the other way against bomb : the horse -elephant attack is probably unsound so soon in the game, but I know Bomb puts a too high value in horse hostage in the begining of the game.

All of this to emphazise the psychological dimension of arimaa in h-h games. Taking a look at recently played H-H games, I was surprised by how often a player begins to play inferior moves once he got a material advantage.

Title: Re: Postal Tournament
Post by 99of9 on Jan 27^th, 2005, 5:47am

on 01/27/05 at 00:59:40, fotland wrote:

I just realized that I can have it play much slower, since opponent time doesn't against it. It could probably meet the time control with 3 hours per move, since the average opponent takes a half day to move. I could do a more sophisticated script that plays first in the game with the least time left, rather than playing them in order.

You never know. We humans might conspire to all play quickly and run bomb out of time. You would really need an adaptive time control.

Regarding rules of the tournament - I have no idea, but I don't think changing the time control is really a change of algorithm.

Title: Re: Postal Tournament
Post by 99of9 on Jan 27^th, 2005, 6:13am

I was just saying to naveed that the level of aggression in arimaa has dramatically increased in the last few months. I've already been under intense fire in nearly all of my postal games. I've split them into two categories - EH attacks, and elephants going around the back of my traps to pop out my horses.

EH attacks
mv 2, robinson
mv 3, belbo
mv 4, ronweasley
mv 5, adanac

around back
mv 3, paul
mv 3, fritz
mv 6, naveed

Against all these onslaughts, I have only managed to play two attacks, an EH against Ron on mv 7, and an around back against naveed on mv 8. Both were counterattacks. I think this tournament may prove that arimaa theory has passed me by.

Title: Re: Postal Tournament
Post by Fritzlein on Jan 27^th, 2005, 7:18pm

on 01/27/05 at 06:13:45, 99of9 wrote:

I was just saying to naveed that the level of aggression in arimaa has dramatically increased in the last few months. [...] I think this tournament may prove that arimaa theory has passed me by.

Far from theory passing you by, you are still writing the book. Opening with the camel back and center is brilliant, and I expect it has a good chance of becoming as standard as your rabbit structure. I'm only glad you uncorked it in time for me to use it in a couple of my late-starting games.

Do you remember how I wasn't going to tell you my potential realization with elephant play? It was nothing more than being aware of opportunities to go around behind a trap in the opening. Big secret, eh? Given that two others played it against you too, it must be an old and/or obvious idea.

Or maybe it's just the general mentality that has changed. For a while folks seemed to think that attacking was more dangerous to the attacker than the defender, but no more. IMHO, the current spate of aggression is good for Arimaa at all levels. It should make the games more interesting to play, more interesting to watch, and shorter.

Unfortunately, I think only one or the other of the types of attack you mention can be correct. If the elephant/horse attack is sound, then going behind a trap to get a horse hostage is useless. It's going to a lot of trouble to get a situation (i.e. using your elephant to hold an enemy horse hostage near a home trap) that the opponent is essentially willing to give you for free with the elephant horse attack.

The results of this tournament will probably dramatically affect opening theory in the future. For example, if using the camel against the exposed horse of an elephant/horse attack is effective, it may make folks abandon the attack altogether. Similarly if the around-the-back attack seems to pay dividends, then folks will have to open more conservatively with silver to prevent it from happening.

Whoever suggested the postal tourney (MrBrain?), my hat is off to you. It has already been a smashing success, and we are just underway. I love being able to log in at any time and have an interesting position to analyze. I love the chance to test new ideas concretely, as opposed to just hypothesizing about them. I love being able to take a day off without penalty. Ten games seems a perfect maximum; more could start to get burdensome, but to have ten means there is always something to do.

And not only is it great fun to be playing in the tournament, it is good for the game. I'll bet that these 80 games will collectively deepen our understanding of Arimaa more than the previous 1000 played on the server. If it turns out (as it now appears possible) that this tournament wraps up in under three months, we should definitely get another one going before the next World Championship cycle comes around.

Title: Re: Postal Tournament
Post by omar on Jan 28^th, 2005, 5:49pm

on 01/27/05 at 00:59:40, fotland wrote:

There shouldn't be any problem if the computer crashes while bomb is thinking about it's move. It can run again later to make the move. The state of the game will not change on the game server until bomb sumbits the move.

I don't see any problem with allowing bomb to run for longer on each move. You still are limited by the time control of the game and using one computer to handle all the games.

If you were running 10 computers each with a copy of Bomb it probably would not be fair to the human opponents who can't make copies of themselves; one for each game :-)

Title: Re: Postal Tournament
Post by omar on Jan 28^th, 2005, 5:58pm

on 01/24/05 at 09:07:37, Fritzlein wrote:

You're right, for scheduled games the clock should automatically start for the first player when the scheduled time arrives. However this could be a problem for interactive games. So I think it should only be done for postal games. We have not played many scheduled postal games so this never really came up. For the next postal tournament I will set it up to auto start the clocks.

Title: Re: Postal Tournament
Post by fotland on Jan 29^th, 2005, 2:29am

I increased Bomb to three hours per move.

It's happy with all of its positions except against Belbo.

Title: Re: Postal Tournament
Post by fotland on Jan 29^th, 2005, 10:18am

How much time are the the strong players using per move in this contest? I bet it's under 10 minutes per move. If so, Bomb has a 20 to 1 time advantage compared to the world championship.

So this tournament lets us see how strong Bomb would be in a regular game if it were running on a 340 GHz CPU.

If Bomb doen't win all of its games, it means I have to do a lot more than just wait for faster computers, to win the human-computer prize.

Title: Re: Postal Tournament
Post by omar on Jan 29^th, 2005, 11:54am

on 01/29/05 at 10:18:37, fotland wrote:

How much time are the the strong players using per move in this contest?

When you view the game after it is over, it shows the average move time for each player in the chat area; you have to scroll down a little to see it.

It is currently calculated based on looking at only when the players sent the moves; so it assumes that the whole time between when your opponent moved and when you sent the next move was spent thinking by you. This is OK for interactive games, but I need to change that for postal games to look at when the player is present and when they are not and use that info as well in determining the actual thinking time.

Title: Re: Postal Tournament
Post by Fritzlein on Jan 30^th, 2005, 10:48am

on 01/29/05 at 10:18:37, fotland wrote:

How much time are the the strong players using per move in this contest? I bet it's under 10 minutes per move.

I find I'm averaging around 10 minutes per move. If school gets busier, that may become less. However, I notice that most of my opponents slowed down from the initial blistering pace, which takes some of the pressure off, and allows me to think 10 minutes per game without feeling rushed.

Simply waiting for faster computers won't be enough, since humans are still rapidly getting better. You would have to improve Bomb as fast as humans are improving AND have computers get faster if you are going to gain ground.

It's no surprise that Bomb thinks it is ahead in most games. In my game I too think the position is objectively much in favor of Bomb. I agree with Bomb's evaluation. But the reason I played four rabbits forward and the elephant/horse attack is that I don't think Bomb will play well in such a position. Even if Bomb wins, it leaves open the question of what would happen if I tried to play the objectively strongest move rather than anti-Bomb moves. But if Bomb loses, that will show a huge remaining gap, i.e. it will show that extra search depth doesn't compensate for Bomb not understanding strategically how to beat off the elephant/horse attack.

For example, on Bomb's last move it could have made a threat to frame my horse that would have been very tricky to counter. Instead it moved its second horse *away* from the contested trap, which meant I didn't have to counter the frame threat and could clear my exposed rabbit from the center. Bomb will face another strategy test on this move: it can again set up a frame threat which is tricky for me to answer. However, I fully expect Bomb won't do this, as part of a pattern of not making the strongest move in this type of position. (After Bomb moves, I'll edit this post to either gloat or eat crow. :-))

[Edit] Looks like I get to gloat, at least over move 7b. Moving the cats away too makes a frame very remote. One would have to conclude that if Bomb can't see a way to immediately force a frame *tactically*, then Bomb has no *strategic* interest in threatening one.

Title: Re: Postal Tournament
Post by fotland on Jan 30^th, 2005, 12:41pm

I haven't given Bomb an evaluation that favors threats that can be countered, even if the coutner is tricky. Against people it is good to set up tricky moves, but the search algorithm assumes the opponent will see everything bomb can see.

I don't see how you can avoid the horse frame, but bomb didn't find a forced horse frame last move. However, it did think you had to defend rather than move your rabbit, so we'll see :)

I thought bomb was very clever the way it set up the horse frame in Naveed's game. I want to see if it is smart enough to rotate out its elephant.

Title: Re: Postal Tournament
Post by Fritzlein on Jan 31^st, 2005, 7:39am

on 01/30/05 at 12:41:14, fotland wrote:

Ah, this isn't what I had in mind, although it would be interesting to attempt. I guess that since Omar provides the opponent name as part of the game state, you could set up Bomb to make the "objectively best" move against other computers, and to make "anti-human" moves against humans at fast time controls in hopes of a blunder.

But anyway what I was referring to was keeping up the pressure. The way I like to attack (as a fallible human) is usually just to put pressure on in a way that limits the defensive choices and forces my opponent to make certain contortions in defending. Often I can't see any concrete gain at the end of my lines, but I still think "This is a position where something has got to give eventually", or "There must be a way for me to get something out of this line, even though I don't see it now."

When Bomb fails to pressure me in this way, I can make my own plans at leisure. At the moment (move 8w) I have only to worry vaguely about Bomb's potential camel attack on the west wing, and am otherwise at leisure to proceed with my strategic aims of the opening: either getting Bomb's small pieces offsides where I threaten them, or making a general rabbit advance on the east wing to threaten remote goal, constrain Bomb's elephant, threaten to liberate my elephant, etc. We'll see whether Bomb at this time control creates enough counterplay to stop me; speedy usually doesn't.

Title: Re: Postal Tournament
Post by 99of9 on Jan 31^st, 2005, 4:09pm

on 01/26/05 at 13:45:37, RonWeasley wrote:

OK, 8 then. And that's my final offer. :P

Well as far as I can tell you just executed a 36 ply forced goal against me!

I'm back in Australia now. Omar could you change my nationality in the player database? Thanks.

Title: Re: Postal Tournament
Post by fotland on Jan 31^st, 2005, 5:30pm

I'm not convinced that an AI breakthrough is needed to build a strong Arimaa program. Bomb uses pretty standard computer chess techniques (PVS, iterative deepening, transposition table, iterative deepening, null move, singular extension, killer and history heuristics, etc.), and it's pretty strong already.

More importantly, the evaluation function and search extensions are far from optimal, and I'm still getting big strength improvements for not much work.

The ultimate bottleneck is more likely to be access to advice from a strong player, since I'm not a very strong Arimaa player myself.

Title: Re: Postal Tournament
Post by Keith on Feb 1^st, 2005, 4:57pm

[quote author=fotland link=board=talk;num=1104134643;start=45#58 date=01/29/05 at 10:18:37]How much time are the the strong players using per move in this contest? I bet it's under 10 minutes per move. If so, Bomb has a 20 to 1 time advantage compared to the world championship.

I can't speak for the strong players. In order to juggle ten games in the time I have available I am taking 2 to 5 minutes per turn averaging about 3 minutes.

Title: Re: Postal Tournament
Post by 99of9 on Feb 2^nd, 2005, 3:19pm

My game against Mr Brain has been reset (and it seems all his other postal tourney ones have disappeared). He was down to about 5 days of thinking time on his second move. Should I start again??

Title: Re: Postal Tournament
Post by MrBrain on Feb 4^th, 2005, 3:27pm

Wow, what happened to all of my games? I was very busy and unavailable until now. I came in to make moves in all of my games, but they have disappeared. Please advise!

Title: Re: Postal Tournament
Post by Fritzlein on Feb 4^th, 2005, 6:32pm

on 02/04/05 at 15:27:24, MrBrain wrote:

Wow, what happened to all of my games? I was very busy and unavailable until now. I came in to make moves in all of my games, but they have disappeared. Please advise!

I don't know whether the moves that already happened can be recovered, but even if they can't at the very least the games should be restarted with three or four days in reserve for you. There must be something special in the eyes of the server about games where no moves have been made except for the initial setup of pieces.

Title: Re: Postal Tournament
Post by Fritzlein on Feb 5^th, 2005, 8:52pm

I ran a spreadsheet on the predicted outcome of the postal tournament, assuming that the ratings at the start of the tournament were accurate. Of course the ratings were not accurate for any number of reasons, but if they were, here is the expected number of points each player should score out of their ten games.

99of9 2171 8.47
Fritzlein 2164 8.42
Belbo 1933 6.07
Omar 1918 5.98
Bomb 1880 5.69
RonWeasley 1851 5.53
Naveed 1810 5.34
Adanac 1780 5.23
Paul 1687 4.56
Robinson 1658 4.42
MrBrain 1605 4.19
Junaid 1570 3.87
Jdb 1556 3.93
Keith 1481 3.04
Kamikazeking 1471 2.96
Rabbitball 1412 2.3

The numbers I'm most curious to compare with the actual results are MrBrain's and Bomb's. MrBrain has long agitated for slower time controls in part because he expects to do better at them, so if he's right he should score vastly better than 4.19, and in fact should have a good shot at winning the whole tournament.

Bomb's score will be interesting because Bomb is actually thinking for three hours per move compared to a few minutes per move for the rest of us. This would suggest a score much higher than 5.69, and indeed also contend for the tournament victory. On the other hand, it is my intuition that computers just aren't very good at long time controls, so I wouldn't be surprised if the prediction of the ratings is accurate for Bomb despite the huge thinking time differential.

Title: Re: Postal Tournament
Post by 99of9 on Feb 5^th, 2005, 9:14pm

Interesting numbers Fritz.

I agree that I'll be looking closely at bot_Bomb and MrBrain, but also at RonWeasley, who hadn't previously played humans. So far he's made a great start of it - beating me, and in a close battle with Belbo. For that matter, Belbo's results will be interesting too, given that he's the human representative this year. Although I guess that's a bit unfair because he'll be putting a lot of effort into defending the title at the same time.

For my part, I don't think I have a hope of getting 8.47. I'm definitely better at short time controls where I can rely on my opponents to overlook my plans :-). And anyway, I've already lost 1... so can only afford a draw from here on in. A lot of my games look like they're going to be very close battles. One very interesting one is my game with Paul, which until a move or two ago had settled into a quasi-equilibrium where neither of us could go for much advantage because both had a horse on either wing.

In fact I think everyone will be nearer to 5.0 than predicted ... my feeling is that without blunders, everyone becomes much more equal in arimaa. But we shall see - perhaps i'm just being optimistic.

Title: Re: Postal Tournament
Post by MrBrain on Feb 6^th, 2005, 11:55am

It would be nice to have the current games and results in a cross table in the Postal Tournament page. Looking at a list of 71 current games doesn't really give anyone a sense of how the games and tournament are progressing.

Title: Re: Postal Tournament
Post by Fritzlein on Feb 6^th, 2005, 2:01pm

on 01/31/05 at 17:30:02, fotland wrote:

In the early days of chess programming, folks had sharply different intuitions as to what it would take to get a comptuer to play chess well. Arguing about it didn't seem to change anyone's mind; what settled it was the brute force searching camp winning lots of games. Similarly Omar's dreams of AI breakthroughs could be crushed by good engineering working well in pratice for Arimaa. I really don't know what to expect: If jdb posted tomorrow and said he got clueless quite strong primarily by AI techniques that wouldn't surprise me either.

I agree that Bomb is quite strong already compared to the level of human play right now. Yet I don't think you have gained any ground from a year ago, since humans are still learning so much about the game so quickly. The ratings gap between Bomb and the top-rated human is about 300 points, just like last year. I expect that next year you will again have to sweat just to keep Bomb within 300 points of the top-rated human.

on 01/31/05 at 17:30:02, fotland wrote:

More importantly, the evaluation function and search extensions are far from optimal, and I'm still getting big strength improvements for not much work.

It was quite palpable how much Bomb improved due to your work this winter. It made it much more fun and interesting to play speedy when some old tricks stopped working. But the areas you list for further improvement (the evaluation function and selecting lines for extended search) are just the sort of things that AI people would love to claim that their techniques are particularly good at.

I wonder if you will soon feel that you hit a wall in being able to improve the hard-coded evaluation.

on 01/31/05 at 17:30:02, fotland wrote:

The ultimate bottleneck is more likely to be access to advice from a strong player, since I'm not a very strong Arimaa player myself.

Ah, but how useful is the advice that I or other players give? I can say that Bomb's last move in our postal game was useless -- just shifting rabbits along the back rank, if anything away from where they needed to be. How would you stop Bomb from making that move next time? Or when I say Bomb should have threatened to frame my horse to keep up the pressure, the idea of "pressure" isn't useful to you. Yet I know for sure that if Bomb just sits there holding my horse hostage with his elephant and threatening nothing else, I will squeeze him to death eventually. It's waiting for me to blunder, and if I don't, I will win.

The most concrete advice I can give to improve Bomb's strategy at the moment is that, when faced with an elephant/horse attack, it MUST frame the attacking horse, or be doomed to long-term disadvantage. It's great if one can bring about the frame without using both one's elephant and camel, but usually they are both necessary. The camel has to come help out if the elephant doesn't have enough friends nearby to do the job.

I am coming to believe that Bomb's current idea of attacking with its camel when it holds a horse hostage is simply inadequate. It doesn't create enough counterplay, particularly when there is no time pressure to make humans blunder tactically. Also, the camel can't operate in the opposing trap near the opposing elephant, and since there is one opposing trap it can't contest, it loses a trickle of cats and rabbits and dogs into that trap. Plugging that leak would help, but I don't think it can substitute for the necessity of framing the hostage horse.

I hope that helps you improve the evaluation function, because I really would like to see Bomb improve and stop me from winning in the same old way. My anti-speedy strategy seems to be working just fine against the postal Bomb that can think for three hours, so a faster chip is probably not the answer.

Title: Re: Postal Tournament
Post by fotland on Feb 6^th, 2005, 10:19pm

The games are far enough along now that it is becoming clear that more thinking time can't overcome Bomb's evaluation deficiencies. Even Bomb thinks that Fritz, Omar, and Paul are up about a rabbit each, and Belbo is up 0.5 rabbit. It only looks to me to have winning positions in two games.

It's passed up several chances to frame pieces or rabbits, so I need a lot more work there. It doesn't understand that you need more than one piece to attack a trap, so that is another obvious improvement. It doesn't undertand a near-hostage, where an advanced weak piece can't retreat, but isn't actually a hostage yet. It doesn't understand that framed doesn't stop a second piece from being hostage at the same time. These are the next evaluation enhancements I'll do.

I'm sure there are also many bugs in the evaluaiton function to be fixed. One problem with deeper search is that it is more likely to find a way to get to position that an infrequent evaluation bug thinks is good.

One way you could help would be to help me identify missed opportunities. For example in the bomb-belbo postal game, at 23b, it looks to me that Bomb could immobilize Belbo's Elephant by moving its Elephant to b5 and rabbit to c7. Later it could pull one of Belbo's rabbits forward to release its own Elephant, and have a winning position. Is there something I'm missing that makes this a bad plan? If not, it shows a big problem with the Elephant mobility evaluation.

Title: Re: Postal Tournament
Post by Paul on Feb 7^th, 2005, 8:13am

Some toughts :

Bomb evaluates his position as inferior in 4 games. In 3 of them, he plays silver.

I think I can put them in two categories : Omar and Fritz games in on side, and Belbo and mine in the other.

Both Omar and Fritz seem to have found a position where Bomb does not know what to play. It has given a rabbit without any counter-play in his game against Omar, and has the same problem in 9b against Fritz : advancing the cat from e8 to e7 is a terrible mistake, clearly made because Bomb has no ideas what to play.

On the other side, both Belbo and I have tried to use at our advantage Bomb setup (this is of course true too for the two other games, but I try to keep things simple).
Putting the camel on the far wing of the opposite elephant when playing silver has led him to a difficult position.

In my game, his phant has to defend both f3 and f6 traps.
His camel has almost no activity so far.

Belbo has choosen to attack directly the camel, so he can pull a rabbit to the c3 trap, and free the other wing for his horse.

I think it's the first reason of the relative weakness of Bomb : to avoid repetitive games, David has randomized the setup. The problem is that bomb do not know what to do whith some of them. It's a big difference between humans and bots : humans begin to play on move 1, choosing a steup where they feel comfortable, and having already some ideas about the type of game they will play. Bomb begins to think on move 2.

In fact, the same problem appears in the middle of the game : Bomb is clearly the reactive player : he does not take initiative, but punish bad moves/planifications of the opponent. When confronted to good defense or flat situation, it simply plays repetitive moves.

Now, I have to say that i'm putting a lot of thinking and time in my game against bomb. I take often 20 to 30 minutes to play my turn, and calculate some sharp variants to a depht of 20-24 plys.
It's the only game of the ten where I spend so much time, and by far.

At this subject, 10 games is way to much in my opinion to play them all at good level.

Title: Re: Postal Tournament
Post by MrBrain on Feb 9^th, 2005, 9:28am

Perhaps I missed this somewhere, but it doesn't seem to be in the rules for the tournament:

How do we determine who is the winner of the tournament? If two players have the same number of wins, what are the tie breakers?

By the way, I think my earlier suggestion got lost in the shuffle, which is to have some sort of cross-table or something that shows results. Otherwise, it's really hard to track what's going on in the tournament.

Title: Re: Postal Tournament
Post by 99of9 on Feb 9^th, 2005, 5:14pm

It's highly unlikely that 2 players will get 100%, because most top players play each other.

If they do not get 100%, then deciding the winner is easy, because the number of points for a loss depends on how long the game took.

I agree a cross table would be nice. However I think it is more an issue of no one having the time and energy to make one yet. Especially since there are only 2 or 3 results!

Title: Re: Postal Tournament
Post by MrBrain on Feb 9^th, 2005, 11:16pm

I understand how the $ goes back to the players. But that doesn't explain the standings, does it? Or does the person getting back the most money win the tournament?

Title: Re: Postal Tournament
Post by Fritzlein on Feb 10^th, 2005, 12:49am

The tournament victory is based on win and losses, but I agree that it would be good to specifiy a tiebreaker. My vote is that the best tiebreaker is (sum of moves in player's losses) minus (sum of moves in player's wins), so that whoever wins fastest and loses slowest in their games has the tiebreak edge.

Title: Re: Postal Tournament
Post by 99of9 on Feb 10^th, 2005, 4:21am

Or the one who had higher rated opponents ;-)

Title: Re: Postal Tournament
Post by Keith on Feb 12^th, 2005, 3:30am

I have not gone away. I don't think I will time out. I am overwhelmed with work. I expect to be working every waking hour through February 15th.

Keith

Title: Re: Postal Tournament
Post by Fritzlein on Feb 12^th, 2005, 9:38am

I am starting to agree with Paul that 10 games is too many. Many next tournament we can play 8 each. To play ten at once you have to be logged on almost every day. That isn't so unusual for me, but I think the burden is wearing on many players.

Title: Re: Postal Tournament
Post by 99of9 on Feb 12^th, 2005, 7:44pm

I'm only playing 8... that's why I was so quick out of the blocks in some games, and so slow in others :-).

More seriously: I think I would prefer to have many games, and slow down the time controls if need be. I'd even be happy with 1move/2days if it meant that everyone could play everyone else. I don't think many games are in danger of hitting 100 moves anymore - arimaa seems to have moved on to a very aggressive style.

Title: Re: Postal Tournament
Post by Adanac on Feb 14^th, 2005, 3:32pm

In December, coincidentally just a few days before I learned about arimaa, I signed up for a few correspondence chess tournaments. With all of those games plus 10 arimaa games, I'm definitely nearing the saturation point! It's been fun, though, and I'm coping by making my chess moves very quickly in the morning and then studying the more difficult arimaa games during my subway/bus commute to work.

In the next Arimaa tournament I'd vote for for 2 days/per move and a round robin format (assuming no more than 20 players) and a 28d reserve. I'd also be perfectly happy to repeat this current format again if other players feel overwhelmed from playing too many games or if it would otherwise compromise the quality of play.

Title: Re: Postal Tournament
Post by Fritzlein on Feb 17^th, 2005, 8:29pm

on 02/12/05 at 19:44:37, 99of9 wrote:

I don't think many games are in danger of hitting 100 moves anymore - arimaa seems to have moved on to a very aggressive style.

Hmmm... but notice that we recently had human-human games of 77 and 80 moves, both more than the previous record. It seems that in spite of the new aggression, positions can stay balanced, or can seize up. In my postal game against Adanac, for example, he attacked recklessly, and I got a horse frame out of it, but I can't untangle my position and the result is as slow as molasses.

Title: Re: Postal Tournament
Post by Adanac on Feb 17^th, 2005, 10:01pm

on 02/17/05 at 20:29:29, Fritzlein wrote:

In my postal game against Adanac, for example, he attacked recklessly...

Unfortunately, you just described half my postal games :) Fortunately, I'm finding that it's possible to recover from these disastrous openings even with the slow time controls.

There was also a recent 102 move draw with some very aggressive opening tactics!

Title: Re: Postal Tournament
Post by 99of9 on Mar 1^st, 2005, 1:47am

Mr Brain and Naveed are getting quite low on time in my games. If either of you see this in time...

Title: Re: Postal Tournament
Post by Keith on Mar 11^th, 2005, 12:12am

Alas I am about to go back to playing hot potato with all my games and lobbing them back over to the other side as quickly as possible. I have a 5 week trial begining March 18.

Title: Re: Postal Tournament
Post by omar on Mar 11^th, 2005, 5:10pm

Im finding that 10 games is a bit much for me. I'm spending most of my Arimaa time on the postal games and not getting a chance to other Arimaa related things. I'm used to playing only one or two postal games at a time at a much slower pace. I really love the no time limit games like the one I have going against Claude. Sometimes we don't make a move for months. The games are really enjoyable because there no preasure.

For the postal tounament I would opt for longer time controls also. Maybe 2 days per move and 1 month reserve like Adanac suggested. But I don't think I could handle more games.

Title: Re: Postal Tournament
Post by Adanac on Mar 14^th, 2005, 10:11am

on 03/11/05 at 17:10:16, omar wrote:

Much to my surprise, arimaa is proving much more difficult with the 1 day time controls than chess. Chess games generally have fewer moves and many of them can be played without much thought such as opening theory, forced recaptures and other obvious moves. Of course, not only does that reduce the amount of thinking required, but it pads the clock too. I’ve played up to 20 correspondence chess games simultaneously in the past with less of a burden than these 10 arimaa games (don’t get me wrong - my use of the word ‘burden’ doesn’t mean that I haven’t greatly enjoyed this arimaa tournament). In arimaa, as in chess, one blunder can lead to long-term suffering, so great care is required in both games, but I find that arimaa has far more ‘crossroad’ positions that require serious analysis. That adds to the enjoyment of each game but it can also annoy the wife ;)

For future tournaments, perhaps we could make 2 separate divisions for ‘casual’ and ‘hard-core’ with the latter using a round-robin format and the former being capped at 6 games with a 2 day limit/move. I’ll definitely play again in future tournaments but next time I’ll be more aware of the time commitment required.

Title: Re: Postal Tournament
Post by Rabbitball on Mar 14^th, 2005, 11:11am

What do you do when the board says it's your move but it won't show any pieces? I think I got a win on time, but I don't know for certain.

Omar, if you see this, check out Game Board 16196...

Title: Re: Postal Tournament
Post by RonWeasley on Mar 14^th, 2005, 11:43am

Interesting comments about time commitment. Because of my browser problems and family responsibilities, these postal games are about the only ones I'm able to play. I haven't always taken the time to make the very best moves. I've been content to make moves that seem not obviously bad, and maybe the most fun. As a result, I seem to be the fastest player in the field. So consider that when I say I like the current time format and number of games, but don't recommend faster or more games.

That said, I find I've had dreams about some of my games. There's definitely effort expended when playing at this level. Trelawney gave me extra credit and 10 points to Gryffendor.

Title: Re: Postal Tournament
Post by Fritzlein on Mar 14^th, 2005, 2:44pm

I think I'd rather have the same pace and only eight simultaneous games, rather than 2 days per move as some people have suggested. The present tournament could drag on for a long time before the final results are in: Omar has yet to finish a single game. At 2 days per move it might take most of a year before the last game ends, and who knows if I'll even be playing Arimaa next year? If it is a contest of endurance now, at 2 days per move it would even be more about commitment and staying power than at present.

The one game I'm clearly losing is to Adanac, and I think it is partially that he is out-working me, thinking harder and longer on every move. I doubt a longer time control would change the balance in my favor. He would still work harder than me, but it would take extra months for the game to finish.

I do like postal Arimaa, though, at the current pace. The blunders get cut way down, and it is time to learn something about theory. Paul and Adanac have taught me that the correct response to having a horse framed is to use the camel to break or threaten to break the frame. (And the Belbo vs 99of9 game shows what happens if you don't do this.) This is very important, as it plays into the ultimate soundness (or unsoundness) of the EH attack. Meanwhile Omar seems to be exploring the exact value of a camel hostage. Against me he got a cat, which I hope is not enough. Against 99of9 he got a dog for the hostage, and that game has remained in dynamic balance for a long time. This serves as better evidence that "early camel hostage = early dog capture" than any half dozen blitz games.

In summary, I like postal games as a means to learn more about Arimaa theory, but I think half the present pace would be too slow for my patience.

Title: Re: Postal Tournament
Post by Adanac on Mar 15^th, 2005, 10:17am

I suggest 2 days/move only if we significantly increase the number of games in future tournaments or if we introduce a new time control for players that don’t have enough time for 1 day/move. For example, we could make 2 groups:

Group 1: Round robin (or some max number of games), 1 day/move
Group 2: Max 6 or 8 games, 2 days/move

I would join group 1 and I assume that all the top-ranked players who can play very quickly and accurately would also join this group. Group 2 would obviously appeal to some of the players that had unpleasant time pressure due to other commitments. And if someone were really gung-ho, they could join both groups to maximize their game-playing. The group 2 games could theoretically last more than one year, but I don’t have any problem with that. It slows down the theory-learning but it ensures that those players will be active members of the website for a long time :)

Title: Re: Postal Tournament
Post by omar on Mar 17^th, 2005, 12:37am

on 03/14/05 at 11:11:30, Rabbitball wrote:

What do you do when the board says it's your move but it won't show any pieces? I think I got a win on time, but I don't know for certain.

Omar, if you see this, check out Game Board 16196...

Sorry I didn't see this earlier. I don't see that game in the current games list any more. I think it must have been the one against MrBrain. I've fixed that so it should be OK now.

Title: Re: Postal Tournament
Post by omar on Mar 17^th, 2005, 12:56am

I am experimenting quite a bit with my postal games; I couldn't resist the opportunity to try new things in a game where I would have plenty of time to think. But as a result I am having to think a lot about my moves. Theres been times when I thought about a move for half an hour and looked about 12 moves deep. The postal tournament has been quite interesting. But I would also perfer fewer simultanious games in the future.

Title: Re: Postal Tournament
Post by 99of9 on Mar 29^th, 2005, 6:30am

Aaaarrggghhh... I can finally sympathize with you Mr Brain - I just did your "send the plan" trick in my game against Omar. I guess I'll soon find out how bad it was!

Title: Re: Postal Tournament
Post by MrBrain on Mar 29^th, 2005, 8:48am

For postal games, the "Send Move" button should require a confirmation, the same way that "Resign" does. That would easily prevent the error that we have so painfully experienced. For me, this type of error pretty much ruined the tournament unfortunately.

Title: Re: Postal Tournament
Post by omar on Apr 3^rd, 2005, 10:15am

I don't know which move you did that on Toby, but I haven't seen anything yet that looks like a blunder or even a weak move. Our postal game is one of the toughest game I've ever played. You are really making me think :-)

Title: Re: Postal Tournament
Post by 99of9 on Apr 4^th, 2005, 2:20am

It was the move when i swung your dog onto the sideline. You can tell it was a bad move because the very next move I had to swing it even further out - which I could have done in the first place.

However what was really bad was that I didn't get to fully consider making an attack myself - I had chances on that move, and haven't had many since!

You're right though, it has been an incredibly active and tense game. My game with Adanac has been very similar at times. Both of you have a similar style (when playing against me at least) ... really ramping up the rabbit pressure, and gradually eroding my backrow.

Title: Re: Postal Tournament
Post by MrBrain on Apr 4^th, 2005, 4:57pm

Sounds like your error was not as serious as a couple of mine, which were instant game losers. In two of my games, I made the exact same mistake, which was when I was trying to eventually get a piece onto one of my traps, I left the trap insufficiently defended. In analysing, this is obviously not a problem, because one will see the next move (lose piece), and take it back to try a different move. But in the actual game, there is no chance of recovery since you've now totally lost control of a key trap deep in your own territory. Hitting "take back", only to have that message window pop up, revealing the error, is like a punch to the stomach. I was just so mad after the second time I did the same stupid thing, I just did not want to continue at all.

Title: Re: Postal Tournament
Post by 99of9 on Apr 9^th, 2005, 7:03am

Personally Mr Brain, I'd say the loss of 4 steps in a close endgame is often easily as bad as the loss of one piece early on.

Omar announced goal one move after the second dog swing. Perhaps I made an error in that one subsequent move (certainly possible since I didn't see Omar's subsequent 5 move forced goal --- 9*4=36 ply no less!!! Wow.) But an extra 4 steps certainly wouldn't have hurt me!

All credit must go to Omar of course. Our games have always been real battles, and this one perhaps more than the rest. From the very beginning of the game, where I got a camel hostage but had to give up material... until the end. In the end he was able to save his camel, and apply so much rabbit pressure, that even when I regained the material lead, my position was hanging by a very thin thread.

I highly recommend anyone examining this game very closely. To my mind it is one of the sharpest games I've ever played. This has got to be my first nomination for the games almanac that somebody suggested on another thread. Adanac's camel sacrifice in our postal game wins my second nomination :-)... about 10 moves later it has paid off with double interest and he now has a significant material lead.