Author: Anthony Cozzie
Date: 12:52:06 06/05/04
Go up one level in this thread
On June 05, 2004 at 15:42:51, Dieter Buerssner wrote: >On June 05, 2004 at 12:32:47, Will Singleton wrote: > >>On June 05, 2004 at 10:13:35, Anthony Cozzie wrote: >>>OK, as has been pointed out by about 25 people, the mistake is not Nxe4, but >>>Bxh6 (a move which somehow I conviently omitted from the my line). >>> >>>3q1rk1/pp1bppbp/3p2pB/8/3Nn1P1/2P1QP2/P1P5/2KR3R b - - 0 18 >>> >>>Even this one is pretty hard for Zappa, it needs 70 seconds to realize Bxh6 is >>>losing and 6 minutes switch to Nf6. >>> >>>1... Bg7xh6 2. Rh1xh6 Ne4-f6 3. Rd1-h1 e7-e5 4. Nd4-f5 Bd7xf5 5. g4xf5 Qd8-a5 6. >>>Qe3-g5 Qa5-a3 7. Kc1-d1 Kg8-g7 8. f5xg6 f7xg6 >>> = (0.50) Depth: 14/31 00:00:46.41 37517kN >>>1 ...Bg7xh6-- >>> - (0.25) Depth: 15/30 00:01:08.74 55010kN >>>1... Bg7xh6 2. Qe3xh6 Ne4-f6 3. g4-g5 Nf6-h5 4. Rh1xh5 g6xh5 5. Rd1-h1 Qd8-a5 6. >>>Rh1xh5 Bd7-f5 7. Nd4xf5 Qa5xf5 8. g5-g6 Qf5xg6 9. Rh5-g5 Rf8-c8 10. Rg5xg6 h7xg6 >>> = (-2.83) Depth: 15/34 00:03:02.47 147329kN >>>1... Ne4-f6 2. Bh6xg7 Kg8xg7 3. Nd4-f5 Bd7xf5 4. g4xf5 Qd8-a5 5. Qe3xe7 Qa5xa2 >>>6. Qe7xb7 Qa2-a3 7. Qb7-b2 Qa3-c5 8. f5xg6 f7xg6 9. Rh1-e1 Rf8-c8 10. Re1-e7 >>>Kg7-h6 >>> = (0.18) Depth: 15/36 00:05:34.28 269390kN > >>The time it takes to find Nf6 after seeing the problem with Bxh6 is rather long >>for some programs. For example, Crafty (3 min), Ruffian (1:30) and Zappa >>(2:30). This is because the problem occurs at a high search depth. >> >>Amateur does better in switching to the right move, taking only 10 sec. It does >>this by "cheating," which is to say, reducing the search depth when a large >>score drop occurs. I don't really see a downside to this. >> >>Crafty >>14 191 11683 124623699 1. ... Bxh6 2. Qxh6 Nf6 >>14 16 30945 341466474 1. ... Nf6 2. Bxg7 Kxg7 >> >>Ruffian >>14 -161 10004 121228508 Bxh6 Qxh6 Nf6 >>14 -5 18402 223090636 Nf6 Bxg7 Kxg7 >> >>Amateur >>16 -243 12517 49364251 Bxh6 Qxh6 Nf6 >>13 -243 12517 49364252 Bxh6 >>13 87 13581 53146356 Nf6 Bxg7 Kxg7 > >Yace is much worse, than all of those. Needs almost 3 min, to fail low (3 1/2 >min to resolve the fail low to -2 score), and 14 (! :-() minutes to come up with >Nf6. Root move ordering is horrible. Nf6 is 35th out of 39 moves, that is tried. >And now, you search all those 33 moves with a window at -2. Many things that got >pruned away with a window close to 0, will not be prunded away now ... > >Another idea, that helps here. Early versions of Yace did not try to resolve the >fail low first, but rather try the other moves first. This also helps >significantly here. Now you try all the other moves with a window close to zero, >and they will fail low with this window much faster, than with the -2 window. >So, even with the same bad root move ordering, instead of 14 minutes, I get 7 >minutes. Sure, nothing to be really proud of, but I thought it was worth >mentioning in the context of your idea. > >Regards, >Dieter Don't feel bad. Zappa resolves Bxd4 to a -2 score as well :) anthony
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