Author: Robert Hyatt
Date: 06:27:09 08/14/00
Go up one level in this thread
On August 13, 2000 at 16:47:33, Ed Schröder wrote: >On August 13, 2000 at 05:23:42, Colin Frayn wrote: > >>On August 13, 2000 at 05:17:29, Colin Frayn wrote: >> >>>Take this position for example; >>> >>>[D]4Q3/2p3p1/7p/p1k1B3/2p1P2P/2P3P1/1r2q3/6K1 w - - >>> >>>which ColChess searches *fully* to depth 13 ply in just over 3 seconds on my >>>p3-450. It is a mate in 9. Crafty sees the mate quite early because of its >>>advanced extensions, but after 30 seconds had still only just reached 11 ply in >>>its search. There are probably better examples where Crafty can't see the mate, >>>and I unfortunately can't remember the board setup before this position, which I >>>know to be one of them. >> >>OK I found the game. This is one position. Unfortunately Crafty again sees the >>mate using its impressive extension code, but ColChess manages to search 18 full >>ply *completely* plus seeing the mate immediately at 19 ply in 46.7 seconds. >>After this time, Crafty has just started searching the 13th ply. See how Faile >>does. >> >>[D]6Q1/2p3p1/5k1p/p3n3/2pBP2P/2P3P1/1r2q3/6K1 w - - >> >>Qf8+ is mate in 12. >> >>Cheers, >>Col > >There are other (cheap) ways. Rebel handles these cases in Q-search. > >00:00:00 04.00 Mate in 12 moves 1.Qf8+ Ke6 2.Qe8+ Kd6 3.Bxe5+ Kc5 > >Ed This would make an interesting discussion. Here is my output on a pretty slow PII/400 notebook: nss depth time score variation (1) 1 0.00 -7.46 1. Qd5 1 0.01 ++ 1. Bxe5+!! 1 0.01 -6.07 1. Bxe5+ Kxe5 2. Qxg7+ Kxe4 3. Qxh6 1-> 0.02 -6.07 1. Bxe5+ Kxe5 2. Qxg7+ Kxe4 3. Qxh6 2 0.03 -6.02 1. Bxe5+ Kxe5 2. Qd5+ Kf6 3. Qf5+ Ke7 4. Qxa5 Qxe4 5. Qxc7+ 2 0.03 ++ 1. Qf8+!! 2 0.04 -4.15 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Qxe5+ 2-> 0.05 -4.15 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Qxe5+ 3 0.05 ++ 1. Qf8+!! 3 0.06 -2.83 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Qxe5+ Kd7 4. Qxa5 3-> 0.09 -2.83 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Qxe5+ Kd7 4. Qxa5 4 0.09 ++ 1. Qf8+!! 4 0.11 0.00 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Be5+ 4-> 0.14 0.00 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Be5+ 5 0.17 0.00 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Be5+ 5-> 0.23 0.00 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Be5+ 6 0.29 0.00 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Be5+ 6-> 0.42 0.00 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Be5+ 7 0.57 0.00 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Be5+ 7-> 0.81 0.00 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Be5+ 8 1.25 0.00 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Be5+ 8-> 1.73 0.00 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Be5+ 9 1.93 ++ 1. Qf8+!! 9 2.60 Mat12 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Qd8+ Ke6 6. Qd5+ Ke7 7. Bc5+ Ke8 8. Qe6+ Kd8 9. Be7+ Ke8 10. Bf6+ Kf8 11. Qe7+ Kg8 12. Qxg7# 9-> 3.50 Mat12 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Qd8+ Ke6 6. Qd5+ Ke7 7. Bc5+ Ke8 8. Qe6+ Kd8 9. Be7+ Ke8 10. Bf6+ Kf8 11. Qe7+ Kg8 12. Qxg7# 10 5.00 Mat12 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Qd8+ Ke6 6. Qd5+ Ke7 7. Bc5+ Ke8 8. Qe6+ Kd8 9. Be7+ Ke8 10. Bf6+ Kf8 11. Qe7+ Kg8 12. Qxg7# 10-> 6.66 Mat12 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Qd8+ Ke6 6. Qd5+ Ke7 7. Bc5+ Ke8 8. Qe6+ Kd8 9. Be7+ Ke8 10. Bf6+ Kf8 11. Qe7+ Kg8 12. Qxg7# 11 9.88 Mat12 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Qd8+ Ke6 6. Qd5+ Ke7 7. Bc5+ Ke8 8. Qe6+ Kd8 9. Be7+ Ke8 10. Bf6+ Kf8 11. Qe7+ Kg8 12. Qxg7# 11-> 13.05 Mat12 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Qd8+ Ke6 6. Qd5+ Ke7 7. Bc5+ Ke8 8. Qe6+ Kd8 9. Be7+ Ke8 10. Bf6+ Kf8 11. Qe7+ Kg8 12. Qxg7# 12 20.79 Mat12 1. Qf8+ Ke6 2. Qe8+ Kd6 3. Bxe5+ Kc5 4. Bd4+ Kd6 5. Qd8+ Ke6 6. Qd5+ Ke7 7. Bc5+ Ke8 8. Qe6+ Kd8 9. Be7+ Ke8 10. Bf6+ Kf8 11. Qe7+ Kg8 12. Qxg7# IE it takes me twice as much depth as you to see this, but 1/2 the time, although I don't know what kind of hardware you are using. For comparison, my quad xeon took .17 seconds...
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