Author: Will Singleton
Date: 15:47:09 02/05/99
Go up one level in this thread
On February 05, 1999 at 17:33:30, Robert Hyatt wrote: >On February 05, 1999 at 14:56:34, John Merlino wrote: > >>On February 05, 1999 at 11:57:56, Djordje Vidanovic wrote: >> >>>A couple of days ago I reported on the successful performance of two French >>>programs, Chess Wizard and Zchess, in the Aubervilliers rapid chess tournament. >>>As this particular position may have been overlooked, and as I believe that it >>>is worth analysing with different chess software, I'll try to bring it up again. >>> >>>White: GM Sekatchev, Black: Zchess 1.2: >>> >>>1. e4 c5 2. Nf3 Nc6 3. Bb5 g6 4. Bxc6 dxc6 5. d3 Bg7 6. h3 Qb6 7. Nc3 Qb4 8. O-O >>>Bxc3 9. a3 Qa5 10. bxc3 Qxc3 11. Rb1 Qa5 12. Bb2 f6 13. e5 f5 14. e6 Nf6 15. Qc1 >>>b6 16. Re1 O-O 17. Qh6 c4 18. dxc4 Bxe6 19. Rxe6 Rf7 20. Ng5 * 1-0 >>> >>> >>>on move 8, Black (Zchess 1.2) played 8...Bxc3. Of the tested programs, the only >>>one not yielding to the temptation was Zarkov 5 playing 8...Nf6, not bothering >>>to capture the Knight, which is, of course, a good move. Other programs, among >>>them Crafty 16.0, according to Zchess's author Franck Zibi, tend to play the >>>same bad move, 8...Bxc3. More info, with comments by Franck 1. e4 c5 2. Nf3 Nc6 >>>3. Bb5 g6 4. Bxc6 dxc6 5. d3 Bg7 6. h3 Qb6 7. Nc3 Qb4 8. O-OBxc3 9. a3 Qa5 10. >>>bxc3 Qxc3 11. Rb1 Qa5 12. Bb2 f6 13. e5 f5 14. e6 Nf6 15. Qc1b6 16. Re1 O-O 17. >>>Qh6 c4 18. dxc4 Bxe6 19. Rxe6 Rf7 20. Ng5 *Zibi, can be found at >>>http://www.forum64.com/. Some tested programs are (AMD K6-2/300): >>> >>>ZChess 1.2 Bxc3 ?? 11 +0.80 >>>WChess 2000 Bxc3 ?? 11 +0.88 >>>Crafty 16.0 Bxc3 ?? 12 +0.13 >>>Chess Genius 6 Bxc3 ?? 8 -0.06 >>>Fritz 5.0 Bxc3 ?? 11 -0.25 >>>Zarkov 5 Nf6 ! :-) 6 -0.19 >>> >>>What does your program play in this position? Bob, you said that you could not >>>reproduce 8...Bxc3. Could you retry it on your Quad? Others? >>> >>>Regards, >>>Djordje >> >>Chessmaster 6000 never gives Bxc3 any serious thought, and almost immediately >>prefers Be6. After thinking for about 3 minutes, it still prefers Be6: >> >>8... Be6 9.a3 Qa5 10.Bd2 Nf6.... with a .54 advantage for white. >> >>jm > > >Be6 looks ugly from a chess point of view. Either Bd7 or Nf6 or moving the >epawn seem more logical to me... I agree Be6 looks odd, but both Chessmaster and my program like it. :) Results for Amateur v0.9i, running on a g3/266: (times and nodes are cumulative) ply score time nodes n/s pv 2 -37 0.01 1509 90540 3 -50 0.07 4354 37320 Bxc3 a3 Qa5 Pxc3 Qxc3 4 -83 0.23 16429 42840 Bxc3 Pxc3 Qxc3 Bd2 Qb2 5 -57 1.04 71033 66540 Bxc3 a3 Qa5 6 -78 2.47 172122 61800 Be6 a3 Qa5 Ne2 Nf6 Bf4 7 -71 10.13 661798 64740 Nh6 a3 Qa5 Bd2 Kg8 Bxh6 Bxh6 Qe2 8 -73 38.01 2458844 64620 Nf6 a3 Qb6 Na4 Qa5 c3 Be6 Bf4 9 -57 177.58 12590469 70740 Be6 Ne2 Nf6 Nf4 Bd7 c3 Qb5 a4 Qb6 10 -78 431.32 27596159 63900 Be6 a3 Qb6 Ng5 Bd7 Na4 Qa5 c3 Nf6 Bf4 The output shows only the results at the end of a ply, not the changes within a ply. So you don't see the reason it changed from Bxc3 in ply 6, which was a -90 or so (100 = 1 pawn). But it took less than 3 seconds to discard Bxc3. The larger than normal node count is because it kept switching the best move. And the scores are from Black's perspective. Hiarcs 6-Mac and MacChess 4.0 both liked Bxc3. So this result of mine is probably an anomaly. Will
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