Author: Peter Skinner
Date: 12:25:16 10/06/04
Go up one level in this thread
On October 06, 2004 at 14:52:46, Peter Berger wrote: >On October 06, 2004 at 13:46:54, Robert Hyatt wrote: > >>On October 06, 2004 at 10:45:46, Tony Hedlund wrote: >> >>>On October 06, 2004 at 08:32:20, Mike Byrne wrote: >>> >>>>Alpha Pocket Crafty 19.17 SE in alpha stage. It is playing within a GUI , will >>>>have most ofthe SE features. >>>> >>>>Personality Opening Books - Plan is now to generate opening books that will >>>>just about every move the "real" personality played in their games for about the >>>>first 20 - 25 moves. Of course, you have to play what their opponents played >>>>for it to stay in the personality book. Fischer personality book will be >>>>completed first. It is very cool. It really give you a sense of the openings >>>>the personality played. >>> >>>Hi Mike, >>> >>>In the Arena Event Forum they say that 19.17 is weaker then earlier 19.xx >>>versions. Is that true? >>> >>>Tony >> >>I do not believe that, no. The changes from earlier 19.x versions are so >>small... >> >>you will still find some that say fritz 5 is the best, that crafty 15.x is >>better than new versions, etc... lots of opinions. I believe the current >>crafty is the best one so far, personally... > >At least when it is about posted results of 19.15 and 19.17, there is some >evidence that 19.17 is weaker. > >Although I didn't collect them I realized that 19.17 was consistently doing >worse in all results posted. I think the main reason for that is flawed testing, testing on 1 pc with ponder on.... Most people do not use the correct books, proper rc file settings, and well just about anything else that can go wrong. We have seen it many times on this forum the horrible testing systems people use, and just how flawed they are. Crafty 19.15 - 19.17 is almost the same engine. I don't see how it is possible that 19.15 would be stronger. From main.c: * 19.15 fix to outside passed pawn code that requires pawns on both sides * * of the board for the side with an "outside passer" or "outside * * candidate" to avoid some bizarre evaluations. sel 0/0 now works * * without crashing Crafty. this would fail in previous versions as * * the hash signature would be modified but not restored. slightly * * more conservative limit on using null-move search to head off a * * few notable zugzwang problems was added. fix to time control * * code to remove a hole that could cause a divide-by-zero at a time * * control boundary. Stonewall detection removed completely as it * * appears to be no longer needed. rook scoring changed to better * * evaluate "open files" by measuring mobility on them. complete * * removal of Phase() (phase.c) and references to the opening, * * middlegame and endgame phases as they were no longer referenced * * anywhere in the code. * * * * 19.16 fix to "Trojan code" to eliminate the time limit exclusion since * * many users still have old and slow hardware, and the time limit * * was not set correctly when PreEvaluate() was called anyway. the * * code to display fail-high/fail-low information was cleaned up so * * that the +1 or +3 now makes sense from the black side where the * * score is really going down (good for black) rather than showing * * a +3 fail high (when Crafty is black) and the score is really * * going to drop (get better for black). Now the fail-high-fail-low * * +/- sign is also relative to +=good for white like the scores * * have been for years. adjustments to pawn evaluation terms to * * improve the scoring balance. "new" now terminates parallel * * threads (they will be re-started when needed) so that we don't * * burn CPU time when not actually playing a game. * * * * 19.17 changes to pawn evaluation to limit positional scores that could * * get a bit out of sane boundaries in some positions. * * * ******************************************************************************* Really there is the removal of useless code, and fixs to scoring. That is about it. Nothing significant between the two. Peter
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.