Welcome, Guest. Please Login or Register.
Dec 15th, 2019, 2:56am

Home Home Help Help Search Search Members Members Login Login Register Register
Arimaa Forum 2008.07.01 Core Rule Changes


   Arimaa Forum
   Arimaa
   General Discussion
(Moderator: supersamu)
   2008.07.01 Core Rule Changes
« Previous topic | Next topic »
Pages: 1 2 3  ...  5 Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print
   Author  Topic: 2008.07.01 Core Rule Changes  (Read 4685 times)
omar
Forum Guru
*****



Arimaa player #2

   


Gender: male
Posts: 976
2008.07.01 Core Rule Changes
« on: Jun 18th, 2008, 11:55am »
Quote Quote Modify Modify

Since I may be traveling on July 1st, I decided to implement the rule changes a little earlier.
 
See this thread for the discussion of the changes.
http://arimaa.com/arimaa/forum/cgi/YaBB.cgi?board=talk;action=display;nu m=1206399208
 
1. First player to lose all rabbits loses the game. If both players lose all rabbits the player who made the most recent move wins. This eliminates the possibility of draw by both players losing all rabbits.
 
2. Repeating the same position (including side to move) for the 3rd time no longer causes the player to lose, but rather the move is considered illegal and rejected. The player should select a different move.
IP Logged
mistre
Forum Guru
*****





   


Gender: male
Posts: 553
Re: 2008.07.01 Core Rule Changes
« Reply #1 on: Jun 18th, 2008, 12:05pm »
Quote Quote Modify Modify

Are these rules in effect for current postal games?
IP Logged

Janzert
Forum Guru
*****



Arimaa player #247

   


Gender: male
Posts: 1014
Re: 2008.07.01 Core Rule Changes
« Reply #2 on: Jun 18th, 2008, 1:54pm »
Quote Quote Modify Modify

on Jun 18th, 2008, 11:55am, omar wrote:
2. Repeating the same position (including side to move) for the 3rd time no longer causes the player to lose, but rather the move is considered illegal and rejected. The player should select a different move.

 
It would be interesting to see, and also check than an edge case is correct, if someone would play a game such that the bot is left with only one repeating move and check that the game server stops the game at the third repetition with an immobilization win.
 
Janzert
IP Logged
omar
Forum Guru
*****



Arimaa player #2

   


Gender: male
Posts: 976
Re: 2008.07.01 Core Rule Changes
« Reply #3 on: Jun 18th, 2008, 2:14pm »
Quote Quote Modify Modify

While I'm at it I also made a change to the Arimaa scoring function. This comes into play when the preset time for the whole game runs out. For example a tournament game might allow a maximum of 4 hours for the game to finish, but neither player has won within this time. The current rules call for the game to be stopped and a score used to determine which player wins. It doesn't happen often and so far only 6 games have been decided by score; none of which where HH games. Currently the score is determined as:
 
Score = R + P*(C+1)
 
  R = Points given for how far the players Rabbits have progressed.
 The row to which each rabbit has progressed is cubed (i.e.
 raised to the power of 3) and these values are summed up to
 determine R.  The first row is 1 and the goal row is 8.
  C = The number of Rabbits the player still has on the board.
  P = Points given for the pieces the player still has on the board.
 The value of each piece on the board is summed.
 
  Value of each piece is:
 
  1 - Rabbit
  2 - Cat
  3 - Dog
  4 - Horse
  5 - Camel
  6 - Elephant
 
See this thread for previous discussion of the scoring function:
http://arimaa.com/arimaa/forum/cgi/YaBB.cgi?board=talk;action=display;nu m=1092524589
 
Ideally I would like to use accelerated time controls proposed by Karl which would eliminate the need for any scoring function, but it is a little difficult to implement and requires a lot of changes throughout the site where ever timecontrols are used or displayed. Since I want to eventually move away from using a scoring function I did not include an area for displaying the score in the new flash client. But if a human player ever needed to figure out the score it would be a real pain with the current formula. So in the mean time I decided to make the scoring function simply be that the player with more pieces on the board wins. In case of a tie the second player to move wins. This is probably not any better, but it's simple to state and simple to determine by looking at the board.  
IP Logged
omar
Forum Guru
*****



Arimaa player #2

   


Gender: male
Posts: 976
Re: 2008.07.01 Core Rule Changes
« Reply #4 on: Jun 18th, 2008, 2:31pm »
Quote Quote Modify Modify

on Jun 18th, 2008, 12:05pm, mistre wrote:
Are these rules in effect for current postal games?

 
Yes, they are in effect now for all games.
IP Logged
omar
Forum Guru
*****



Arimaa player #2

   


Gender: male
Posts: 976
Re: 2008.07.01 Core Rule Changes
« Reply #5 on: Jun 18th, 2008, 2:47pm »
Quote Quote Modify Modify

on Jun 18th, 2008, 1:54pm, Janzert wrote:

 
It would be interesting to see, and also check than an edge case is correct, if someone would play a game such that the bot is left with only one repeating move and check that the game server stops the game at the third repetition with an immobilization win.
 
Janzert

 
I did not add this check. Currently the server would keep rejecting the 3rd repetition move and the game would end with the bot losing on time instead of immobilization. Actually to check this properly the server needs to generate player B's moves when player A's move is received and see that player B only has one move and that move is a 3rd repetition. This adds more overhead to the move checking logic which would have to be run on every move check but would only trigger in very rare cases.
 
IP Logged
Fritzlein
Forum Guru
*****



Arimaa player #706

   
Email

Gender: male
Posts: 5928
Re: 2008.07.01 Core Rule Changes
« Reply #6 on: Jun 18th, 2008, 3:08pm »
Quote Quote Modify Modify

I'm thrilled with both of these rule changes.  Thank you for implementing them, Omar!
 
Simplifying the score function can't hurt, although it mostly reminds me that we are lucky no game between humans has ever run out of time.
 
I'm a little leery of rule change in the middle of a tournament, since RonWeasley vs. mistre in the Postal Mixer might just have changed from a draw to a loss for mistre.  But if mistre is not complaining, then I should hold my peace.  Clearly he has not been playing for the draw anyway.
« Last Edit: Jun 18th, 2008, 3:13pm by Fritzlein » IP Logged

omar
Forum Guru
*****



Arimaa player #2

   


Gender: male
Posts: 976
Re: 2008.07.01 Core Rule Changes
« Reply #7 on: Jun 19th, 2008, 2:19am »
Quote Quote Modify Modify

on Jun 18th, 2008, 3:08pm, Fritzlein wrote:

I'm a little leery of rule change in the middle of a tournament, since RonWeasley vs. mistre in the Postal Mixer might just have changed from a draw to a loss for mistre.  But if mistre is not complaining, then I should hold my peace.  Clearly he has not been playing for the draw anyway.

 
I was so caught up with trying to make these changes before I leave for travel, I forgot to consider the effect on the postal games. Sorry mistre.
IP Logged
aaaa
Forum Guru
*****



Arimaa player #958

   


Posts: 758
Re: 2008.07.01 Core Rule Changes
« Reply #8 on: Jun 19th, 2008, 4:22am »
Quote Quote Modify Modify

It would have to be beyond ironic if draws were abolished just about when we would finally get our first legitimate one.
« Last Edit: Jun 19th, 2008, 4:23am by aaaa » IP Logged
RonWeasley
Forum Guru
*****




Harry's friend (Arimaa player #441)

   


Gender: male
Posts: 882
Re: 2008.07.01 Core Rule Changes
« Reply #9 on: Jun 19th, 2008, 7:19am »
Quote Quote Modify Modify

Omar,
 
If you look at the replay of a game won by rabbit extermination, the reason-for-losing field next to the non-winner's name says "undefined".  I'm thinking you intend to put something like "No rabbits" there.
 
This rule had some effect on my postal game with mistre.  Near the end, there were lines mistre might have tried where he would have had to trade his last rabbits for my horse and played for a draw.  I remember seeing extermination chances for my rabbits when planning my move and avoiding those lines, partly because I didn't recall if that was a tournamant rule, but partly because I was playing for a win.  I didn't think mistre could get a draw if he would have tried for one, contrary to one of Fritz's comments, and I think mistre had enough position that he was right to play for the win.
IP Logged
mistre
Forum Guru
*****





   


Gender: male
Posts: 553
Re: 2008.07.01 Core Rule Changes
« Reply #10 on: Jun 19th, 2008, 10:08am »
Quote Quote Modify Modify

I was fine with the rule change.  It really didn't dictate how I approached the endgame - RonWeasley forced me into goal threat mode after he hostaged my H.
 
Don't get me wrong, I would have preferred a draw over a loss, but I did not see a strategy that would produce such a result and since Ron was actively avoiding it, it wasn't ever really an option.
 
This game just goes to prove that even with so few rabbits on the board, it is still most advantageous to play for the win (extermination rule or not).  I felt like if I played more defensive, I would have lost earlier.
 
 
IP Logged

omar
Forum Guru
*****



Arimaa player #2

   


Gender: male
Posts: 976
Re: 2008.07.01 Core Rule Changes
« Reply #11 on: Jun 19th, 2008, 1:30pm »
Quote Quote Modify Modify

on Jun 19th, 2008, 7:19am, RonWeasley wrote:

If you look at the replay of a game won by rabbit extermination, the reason-for-losing field next to the non-winner's name says "undefined".  I'm thinking you intend to put something like "No rabbits" there.

 
For now only the Flash V2 client displays it properly.
IP Logged
Fritzlein
Forum Guru
*****



Arimaa player #706

   
Email

Gender: male
Posts: 5928
Re: 2008.07.01 Core Rule Changes
« Reply #12 on: Jun 19th, 2008, 4:18pm »
Quote Quote Modify Modify

on Jun 19th, 2008, 7:19am, RonWeasley wrote:
I didn't think mistre could get a draw if he would have tried for one, contrary to one of Fritz's comments, and I think mistre had enough position that he was right to play for the win.

Just to clarify, I never analyzed the position.  I didn't mean to assert that mistre could have gotten a draw by playing for one.  What I meant by
 
on Jun 18th, 2008, 3:08pm, Fritzlein wrote:
I'm a little leery of rule change in the middle of a tournament, since RonWeasley vs. mistre in the Postal Mixer might just have changed from a draw to a loss for mistre.

is that it was the type of position where a rule change could make a difference.  I'm sure that, since two players both agree that no draw was in the offing, none ever was.
IP Logged

RonWeasley
Forum Guru
*****




Harry's friend (Arimaa player #441)

   


Gender: male
Posts: 882
Re: 2008.07.01 Core Rule Changes
« Reply #13 on: Jun 20th, 2008, 3:52am »
Quote Quote Modify Modify

Sorry, Fritz.  I was a bit awkward in my wording.  I should have said something like "contrary to speculation" and not singled you out and changed your meaning.  And I agree that discussion about the possibility of a draw was appropriate for this game.
IP Logged
omar
Forum Guru
*****



Arimaa player #2

   


Gender: male
Posts: 976
Re: 2008.07.01 Core Rule Changes
« Reply #14 on: Jun 20th, 2008, 4:57am »
Quote Quote Modify Modify

on Jun 18th, 2008, 1:54pm, Janzert wrote:

It would be interesting to see, and also check than an edge case is correct, if someone would play a game such that the bot is left with only one repeating move and check that the game server stops the game at the third repetition with an immobilization win.
 
Janzert

 
I thought of a way to check this more efficiently and added this check now. Only problem is that it is very hard to test this condition. If someone wants to test it that would be great.
 
It may also be possible for a player to have more than one move and all of those moves are a third time repeat. I don't check for this. I only check for the case where the player has only one move and it is a third time repeat.  
IP Logged
Pages: 1 2 3  ...  5 Reply Reply Notify of replies Notify of replies Send Topic Send Topic Print Print

« Previous topic | Next topic »

Arimaa Forum » Powered by YaBB 1 Gold - SP 1.3.1!
YaBB 2000-2003. All Rights Reserved.