Author: Uri Blass
Date: 06:25:51 01/01/03
Go up one level in this thread
On January 01, 2003 at 09:05:26, Uri Blass wrote: >On January 01, 2003 at 08:48:39, Omid David Tabibi wrote: > >>[D] r1bqk1nr/pppp1ppp/2n5/2b1p3/1PB1P3/5N2/P1PP1PPP/RNBQK2R b KQkq b3 0 4 >> >>The Evans Gambit, arising after 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4, is a good >>example of positional material sacrifice. By sacrificing his b pawn, white gains >>a number if precious tempos, thus seizing the opening initiative. While the 4.b4 >>gambit might not be better than the other 4th moves here, it usually reaches a >>balanced position in which white has enough compensation for the sacrificed >>pawn. >> >>Now let us see how the top engines evaluate this position. There is not much >>tactics involved here, so this gives us a good opportunity to compare the >>programs' evaluation (their chess knowledge). >> >>In the table below, the evaluation of each engine is recorded after 1 minute >>analysis (since the evaluation is largely positional, no significant score >>change was noticed from one ply to another, so most probably even deeper >>searches will not change the result): > >It may be interesting to check. > >It is possible that deep search may translate positional advantage that the >program does not understand to positional advantage that it understands. > >> >> >>Engine Score >>------ ----- >>Junior 7 0.06 >>Fritz 7 -0.41 >>Shredder 6.02 -0.33 >>Chess Tiger 14 -0.82 (Gambit Tiger 2 also produced the same score) >>Hiarcs 8 -0.84 >>Crafty 19.1 -0.81 >> >> >>Interesting points: >> >> - Junior 7 was the only program who evaluated the position realistically. >> >> - Gambit Tiger 2 which is tuned for sacrificial play, did not evaluate >> the position differently from Chess Tiger 14. >> >> - Hiarcs 8 which is said to incorporate the most chess knowledge, displays >> the least chess understanding in this position! (Conclusion: more chess >> knowledge does not necessarily mean better evaluation.) > >I already read that hiarcs is more materialistic than Fritz when Fritz is more >materialistic than Junior. > > >> >>Omid. >> >>P.S. An analysis of Fritz 8 and Shredder 7 will be appreciated. > >Movei gives -0.65/11,-0.62/12,-0.58/13,-0.58/14 from white's point of view. > >Uri Now Movei say -0.55/15 depth=15 +0.55 c5b4 c2c3 b4a5 e1g1 g8f6 c4b5 a5b6 d1a4 d8e7 d2d3 e8g8 b1d2 e7e6 c1a3 c6e7 Nodes: 240085635 NPS: 155678 Time: 00:25:42.19 If people are interested they can give public movei to analyze it for some hours on better hardware and report the results. I used 64 mbytes on A1000 and public movei(latest movei has no difference in the evaluation for this moment and I prefer to give results that can be reproducable by other people). I suspect that movei may get depth 17 or 18 if you give it some hours on fast hardware. Uri
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