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        Arimaa >> General Discussion >> Playable bots
        
(Message started by: mistre on Aug 8^th, 2007, 2:27pm)

Title: Playable bots
Post by mistre on Aug 8^th, 2007, 2:27pm

Looking at past archives - I see that people were playing against bots with names such as bot_speedy, bot_lightning, bot_arimaanator, and bot_fairy. What happened to these and why are they not on the ladder?

Also, any plans for 2007 bots? It would be nice to have some fresh bot blood on the ladder to play against.

Title: Re: Playable bots
Post by Fritzlein on Aug 8^th, 2007, 8:50pm

The only bots on the ladder are ones for which the code was donated to Omar, or which participated in some Computer Championship, thereby granting Omar the right to put them on-line. Like you, I want to see the new bots from 2007, namely Fairy and Zombie, put into the ladder. On the other hand, the need for a new interface has been so pressing for so long, I'd rather Omar put his time into developing that, if he has to choose.

The bots without a year in their names are usually run on the developer's own computer, so they are usually available only while the developer is testing out new code. In particular bot_speedy and bot_lightning were versions of Bomb playing at 30 seconds and 15 seconds respectively, from Fotland's computer. You probably won't get a chance to play either until someone beats bot_Bomb2005 in some Computer Championship, forcing Fotland out of retirement. Bot_haizhi was probably the strongest bot that no humans have had a chance to play, because Haizhi Zhong never entered it in a Computer Championship.

One special case is bot_Arimaanator. It is an old, buggy version of Bomb, predating Bomb2004, and predating the discovery of the camel hostage strategy. Bot_Arimaanator plays very aggressively with its pieces, so much so that it is very difficult to beat it with an elephant-horse attack, because it will counter-attack even more forcefully. This was the steamroller Bomb that was scaring folks into thinking humans might lose the Arimaa Challenge in the first year. It would be excellent to have bot_Arimaanator in the ladder, because it forces one to learn about camel hostages in a way that no other bot does.

Omar bought his copy of bot_Arimaanator from Fotland, and he has the right to run it on the server, which he did for a long time. Indeed, in the old days the "bot ladder" consisted of only three bots: bot_ShallowBlue, bot_Arimaazilla, and bot_Arimaanator. Unfortunately, bot_Arimaanator runs only on Windows, so it can't be started and controlled like the Linux bots that make up the present-day ladder. Still, it would be possible to put bot_Arimaanator on a spare Windows machine somewhere and make it available for play once again.

Maybe if you beg Omar and me hard enough, he'll lend me the bot_Arimaanator executable to run on my home Windows computer for challenges in the game room. It would be interesting to see how a new crop of players encounter the old nemesis.

Title: Re: Playable bots
Post by Fritzlein on Aug 16^th, 2007, 9:14pm

Omar has loaned me the bot_Arimaanator code, so I will try to put the bot up from time to time for play in the game room. I hope you will enjoy the challenge, mistre, and not conquer bot_Arimaanator too easily.

Title: Re: Playable bots
Post by Fritzlein on Aug 18^th, 2007, 9:17am

Mistre (and everyone), what would be your preferred time control for playing bot_Arimaanator? Traditionally it played at a time control of two minutes per move, but only using a bit over one minute per move itself. I can speed that up somewhat if it makes it easier to get a game in, or keep it slow if folks prefer a more strategic encounter.

Title: Re: Playable bots
Post by arimaa_master on Aug 19^th, 2007, 12:49pm

on 08/18/07 at 09:17:32, Fritzlein wrote:

45 sec or more would be fine, it is very good bot (I think it should play WCC 2008 - I know I know that it is predecessor of bomb but anyway :) )

Title: Re: Playable bots
Post by Fritzlein on Aug 19^th, 2007, 2:41pm

I would also like bot_Arimaanator to play in the 2008 Computer Championship. My hunch is that even this old, buggy version of Bomb is better than all the other bots, and would come in second place to Bomb2005. However, it is only a Windows executable, not code that can be compiled on Linux, as far as I know. That means bot_Arimaanator can't compete on a level playing field.

One fun thing I could do is have bot_Arimaanator compete in the 2008 Postal Tournament, especially if there is no other bot taking part.

Later on I will switch back to one-minute per move games, playing under the bot_Arimaanator account.

Title: Re: Playable bots
Post by arimaa_master on Aug 19^th, 2007, 2:49pm

on 08/19/07 at 14:41:56, Fritzlein wrote:

Yes, Yes, Yes, I would be very happy to see this bot in the 2008 Postal Tournament, I think that this bot could play even better performance than bomb two years ago.

Title: Re: Playable bots
Post by aaaa on Aug 19^th, 2007, 4:41pm

I would expect there being a limit to one bot per developer to prevent shenanigans. It would also defeat the purpose of finding out the best bot if the developer himself has already superseded it with another.

Title: Re: Playable bots
Post by Fritzlein on Aug 19^th, 2007, 5:39pm

Oh, I forgot, there is a limit of one bot per developer in the Computer Championship. Now that I think about it, the rule is essential. But the Postal Tournament no longer even has any prize money on the line, just a refundable participation fee, so it makes sense that it should be a more relaxed forum for experimentation. I would love to see the rules to the Postal Tournament tweaked to encourage developers to enter, for example allowing mid-tournament software modifications and arbitrary hardware.

Title: Re: Playable bots
Post by mistre on Aug 21^st, 2007, 7:12pm

on 08/16/07 at 21:14:06, Fritzlein wrote:

Thanks. I have played it once so far and lost - so no need to worry about conquering it too easily. I would like to see the time control at 45 sec instead of 1 min so a game will take less time.

Does it play differently based on the time control set?

Title: Re: Playable bots
Post by Fritzlein on Aug 21^st, 2007, 7:41pm

I'm glad you enjoyed playing the old bot on the block.

on 08/21/07 at 19:12:55, mistre wrote:

I would like to see the time control at 45 sec instead of 1 min so a game will take less time.

OK, 45 seconds it is, although I'm not sure then whether to have it log in as bot_Arimaanator or bot_ArimaanatorFast. I suppose the latter, since 45 seconds is closer to 30 than to 80 or so, as Arimaanator used to take.

Quote:

Does it play differently based on the time control set?

The evaluation is identical, but it might play different moves when it searches to a different depth. I suspect there is an odd/even effect, such that any bot is more defensive when it searches two ply and more aggressive when it searches three ply. However, Arimaanator's quiescence search would minimize the importance of the full-width search depth, and Arimaanator's aggressive nature is deeply ingrained. Furthermore, between half a minute and two minutes it usually searches somewhere between two and three ply anyway, which I would guess would mask the odd/even effect, which might not exist in the first place.

Title: Re: Playable bots
Post by IdahoEv on Aug 23^rd, 2007, 10:02am

FWIW, I'm more than happy to give Omar whatever he needs to put Zombie2007 in the bot ladder.

Title: Re: Playable bots
Post by Fritzlein on Aug 23^rd, 2007, 11:27am

on 08/23/07 at 10:02:22, IdahoEv wrote:

FWIW, I'm more than happy to give Omar whatever he needs to put Zombie2007 in the bot ladder.

I believe that merely by entering the 2007 Computer Championship you gave Omar what he needs. However, when the Arimaa server's security was compromised, and Omar had to restore everything, apparently he forgot to restore the directory with all the 2007 CC bots. :o So he may ask you for that code at some point (after completing the new interface, etc.)

Title: Re: Playable bots
Post by mistre on Aug 27^th, 2007, 1:40pm

Is Gnobot2006 ever going to come back online? I have unfinished business with that bot...

Title: Re: Playable bots
Post by The_Jeh on Aug 27^th, 2007, 3:56pm

I'd like to know about bot_Bomb2004CC vs. bot_Bomb2005CC. Is Bomb2005 better than Bomb2004 despite Bomb2004 being rated several points higher? And does anyone know what tweaks were made to upgrade it to Bomb2005?

By the way, for consistency I would call 45 seconds something like "bot_Arimaanator45s" After all, you're not getting the same thing as you would against a 30s think time.

Another question - why do bots that have newer counterparts retain the "CC" at the end of their name?

And yet one last question - Has anyone straight up asked Fotland if he plans on writing a new bot in the future? Or has anyone asked him to do some upgrading on Bomb? Fotland isn't a big Arimaa fan, but I'll bet just expressing our sincere gratitude for his important contribution would be enough to make him deem a small Bomb improvement worthwhile. I don't see how another bot usurping him is much more motivation - unless he cares more about the computer title than the Arimaa challenge prize money. Maybe that's it - although I could do some stuff with $500.

Title: Re: Playable bots
Post by Fritzlein on Aug 27^th, 2007, 10:25pm

on 08/27/07 at 15:56:20, The_Jeh wrote:

My impression from having played both bots is that Bomb2005 is slightly more difficult to get the best of in several ways. Bomb2004 undervalues rabbits more, and overvalues camels and camel hostages more. This makes Bomb2004 easier to nickel-and-dime. Bomb2005 learned to value its last few rabbits more highly than the early ones. Also Bomb2005 learned to activate its camel after taking a horse hostage with its elephant, which isn't the best strategy, but is at least better than hanging back and getting swarmed.

Other than that, I'm guessing Bomb2005 was mostly tweaks and bugfixes that individually don't seem so important, but collectively represent improvement. I'm pretty sure that Bomb2005 would win more than half against Bomb2004, and that Bomb2005 is tougher for human opponents to beat.

The reason Bomb2004CC is higher-rated is probably that it bores its opponents to death. At three minutes per move, hardly anyone plays Bomb2004CC a second time, unless they are having difficulty winning. Meanwhile Bomb2005Blitz is rated lower than Bomb2005Fast, perhaps because it is quicker to win a long series of blitz, even though Bomb2005Blitz is surely the toughest bot on the server.

Quote:

And yet one last question - Has anyone straight up asked Fotland if he plans on writing a new bot in the future? Or has anyone asked him to do some upgrading on Bomb?

I believe I have expressed my gratitude for his work and eagerness for further improvements, and I don't think I'm the only one. But not only does he have no monetary incentive to improve Bomb, he has only a small community to discuss refinements with. When he posted some of the many tricks he used to make Bomb so strong, nobody said, "Oh, that's great, I'm going to implement it and take it a step further." If I'm not mistaken, he wants other developers to catch up, because it is no fun to be in competition with only yourself. Contrast this to Go, where he not only has strong monetary incentives, but also there is a big community of competitors to keep him hopping. (Speaking of which, I wonder if he's got his own UCT bot by now.)

By all means, please contact him on behalf of the community, express our gratitude and invite him to come back. It can't hurt to ask!

Title: Re: Playable bots
Post by The_Jeh on Aug 27^th, 2007, 11:08pm

Hmm. I'd try to write my own bot if I had any programming expertise. I've only done programming using REALbasic, which simplifies programming for me at the cost of being less versatile for projects such as these.

If I were to invent an algorithm for evaluating a board position, is there any kind person who would be willing to plug it into a bot for me? To plug an algorithm into some pre-made move-generating code couldn't take more than the time one spends playing on the server, could it?

Title: Re: Playable bots
Post by IdahoEv on Aug 28^th, 2007, 11:49am

on 08/27/07 at 23:08:03, The_Jeh wrote:

If I were to invent an algorithm for evaluating a board position, is there any kind person who would be willing to plug it into a bot for me?

If it were reasonably easy to implement, I'd be happy to drop your eval into the Fairy/Zombie search system to see how it performs.

Title: Re: Playable bots
Post by The_Jeh on Aug 28^th, 2007, 12:58pm

on 08/28/07 at 11:49:10, IdahoEv wrote:

If it were reasonably easy to implement, I'd be happy to drop your eval into the Fairy/Zombie search system to see how it performs.

Thank you very much. I have an idea, but I will have to take some time to get it all arranged.

Title: Re: Playable bots
Post by IdahoEv on Aug 28^th, 2007, 4:06pm

on 08/28/07 at 12:58:26, The_Jeh wrote:

Thank you very much. I have an idea, but I will have to take some time to get it all arranged.

The best way to do it would be to not just write an explanation of how it works, but to provide a few boards (in arimaa notation) along with how many points they should score. That way I can test that my code is doing what you want.

Title: Re: Playable bots
Post by The_Jeh on Aug 28^th, 2007, 5:17pm

I think that would be best, too. I will have do do something like that to make sure my algorithm meets my expectations, anyway. As it is, does Fairy/Zombie do any pruning, or does it search all branches? For simplicity, I do not need pruning.

Title: Re: Playable bots
Post by IdahoEv on Aug 29^th, 2007, 5:32pm

Fairy/Zombie does intelligent ordering for cutoffs (killer moves heuristic, etc.) but does not do any forward pruning.

Title: Re: Playable bots
Post by The_Jeh on Aug 29^th, 2007, 6:20pm

Okay. Would you send me your e-mail address via private message on this forum? I would like to do any transmission of my algorithm privately so as to keep its workings a secret. However, I do not anticipate a big success; but who knows?