Author: Uri Blass
Date: 10:59:51 06/25/04
Go up one level in this thread
On June 25, 2004 at 13:24:34, Dezhi Zhao wrote: >On June 25, 2004 at 12:07:03, Uri Blass wrote: > >>On June 25, 2004 at 09:43:43, Dezhi Zhao wrote: >> >>>On June 24, 2004 at 20:18:34, Keith Evans wrote: >>> >>>>On June 24, 2004 at 15:07:41, Dezhi Zhao wrote: >>>> >>>>>On June 24, 2004 at 00:24:39, Keith Evans wrote: >>>>> >>>>>>On June 23, 2004 at 13:48:03, Vincent Diepeveen wrote: >>>>>> >>>>>>>On June 22, 2004 at 07:46:02, TEERAPONG TOVIRAT wrote: >>>>>>> >>>>>>>> >>>>>>>>Hi, >>>>>>>> >>>>>>>>I've never seen any downloadable Chinese chess program that can match >>>>>>>>a strong human player. IMHO, it's much more difficult to create a master >>>>>>>>level program than in chess. In chess, when you lose the first pawn,it's >>>>>>>>likely that you'll lose the game eventually. But, in Chinese chess, you may >>>>>>>>find yourself in trouble after you have 1-2 pawns up in the opening. >>>>>>>>And you have to handle many specific endgame positions differently. >>>>>>> >>>>>>>>Regards, >>>>>>>>Teerapong >>>>>>> >>>>>>>There is no commercial motivation for writing chinese chess programs that's the >>>>>>>sole reason why the more popular of the 2 games is dominant in computer games. >>>>>>> >>>>>>>I know the rules of both games and can assure you that it is for an outsider >>>>>>>much harder to write a chessprogram beating the strongest chessprograms, than it >>>>>>>is to write a chinese chess program beating the strongest chinese chess >>>>>>>programs. >>>>>>> >>>>>>>Note that both require a big effort, but chinese chess is at a much lower level >>>>>>>thanks to commercial driven developments in chess. >>>>>> >>>>>>Don't you think that rules for xiangqi are more complicated that for chess? (See >>>>>>Chapter 4 Section 4 of http://www.clubxiangqi.com/rules/asiarule.htm) I don't >>>>>>think that there is any free Xiangqi program which understands these rules. If >>>>>>you could distill these rules into some trivial C code, then you could help to >>>>>>improve the computer referees at the online servers, and you could also help to >>>>>>improve the state of non-commercial Xiangqi software. >>>>>> >>>>> >>>>>Agreed. The rules are so complicated that a restricted search seems to be >>>>>necessary for an implementation. Chinese rules are even more complicated than >>>>>Asian rules. >>>>> >>>>>>It is my belief that Xiangqi masters could exploit programs which don't >>>>>>completely understand these rules, but I don't have any firm evidence of this. >>>>>>It's difficult to find much written by masters which has been translated into >>>>>>English. It's not clear to me that the rules are well defined in >>>>>>computer-computer competitions, in fact there are some that believe that the >>>>>>rules should be simplified for computers. I assume that masters insist on some >>>>>>official rules when playing computers, but I don't know this for a fact. (Either >>>>>>AXF or CXA rules?) >>>>> >>>>>The effect is more than that you have described. If your program does not >>>>>understand rules, the search can not produce a correct move in too many cases. >>>>>I don't see any trend CXA wants to simplify the rules. Instead they tend to make >>>>>it more complex in each revison. Believe it or not, some Xiangqi masters even >>>>>admmitted to me that they do not understand the arcane rules well:) >>>> >>>>Do you have any examples of really decisive wins by masters over computer >>>>programs? The shorter the better. >>>An example come to my mind at this time is a game between my program and a >>>Hongkong master at ICCS years ago. The program had a wining position, ahead with >>>materials. However it only knew CXA rules and the game was supposed to be under >>>Asian rules. The master drew the game by a one-check and one-mate-threat >>>repetition which is not allowed under Chinese rules. Should the program know >>>Asian rules, it could have won the game. >> >>I see no interest in games when the hard part is to know the rules. > >still far from such extent:) > >>The hard part should be to choose the correct move and not to find the list of >>legal moves. >> >>I can also define rules that will make it very hard for humans to play the game. >> >>For example define a game that is identical to chess except the list of legal >>moves that is different. >> >>Players need to play every time one of the moves that win the most material >>based on 7 ply brute force search(if there is mate in 4 they have to play the >>move that lead to the shortest mate and if they can win a pawn by 7 ply >>conmbination but not more than it they have to play the move that wins a pawn >>based on 7 ply brute force search). >> >>Do not confuse win a pawn based on x ply search with real winning of material >>and if we play the same game with 1 ply instead 7 plies then every side has to >>play the biggest capture in 1 ply except cases that the biggest capture >>generates stalemate and in this case they have to play it if all the alternative >>leads to position with material disadvantage. >> >>Computers can do 7 ply brute force search and find the list of the legal moves >>but it will be very hard for humans only to find if a move is legal. >> >>Uri > >I think the major cause of complicated Xiangqi rules is to prevent easy draws. >Perpetual checks, as for a simple example, is an easy-to-do in Xiangqi even for >the losing side because a king is confined to only 9 squares. Therefore, >perpetual checks are illegal. I do not think that rule that forbid perpetual check is hard to implement in software. Simply consider every check that force repetition as illegal move. Uri
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.