Author: Michael Henderson
Date: 07:41:04 09/03/04
Go up one level in this thread
On September 03, 2004 at 10:16:46, Stuart Cracraft wrote: >On September 03, 2004 at 10:13:35, Michael Henderson wrote: > >>On September 03, 2004 at 08:57:49, Andrew Platt wrote: >> >>>Just to show how slippery this position is, I just tried it with Crafty 19.17 >>>and it fails to find the mate in ply 9 and now takes a long time to find it: >>> >>>unable to open book file [./book.bin]. >>>book is disabled >>>unable to open book file [./books.bin]. >>> >>>Crafty v19.17 >>> >>>White(1): ponder off >>>pondering disabled. >>>White(1): setboard 4r1k1/p1qr1p2/2pb1Bp1/1p5p/3P1n1R/1B3P2/PP3PK1/2Q4R w - - >>>White(1): analyze >>>Analyze Mode: type "exit" to terminate. >>> clearing hash tables >>> time surplus 0.00 time limit 22.50 (3:30) >>> depth time score variation (1) >>> 7 0.26 +1 1. Kf1!! >>> 7 0.57 -1.88 1. Kf1 Kf8 2. Bc2 c5 3. dxc5 Qxc5 4. >>> Qd2 Qd5 >>> 7-> 0.59 -1.88 1. Kf1 Kf8 2. Bc2 c5 3. dxc5 Qxc5 4. >>> Qd2 Qd5 >>> 8 1.52 +1 1. Kf1!! >>> 8 3.41 -0.99 1. Kf1 a5 2. Rxh5 gxh5 3. Rxh5 Re1+ >>> 4. Kxe1 Nxh5 5. Qg5+ Kf8 6. Qh6+ Kg8 >>> 7. Qxh5 >>> 8-> 3.46 -0.99 1. Kf1 a5 2. Rxh5 gxh5 3. Rxh5 Re1+ >>> 4. Kxe1 Nxh5 5. Qg5+ Kf8 6. Qh6+ Kg8 >>> 7. Qxh5 >>> 9 7.75 -0.70 1. Kf1 a5 2. Rxh5 gxh5 3. Rxh5 Re1+ >>> 4. Kxe1 Nxh5 5. Qg5+ Kf8 6. Qh6+ Ke8 >>> 7. Qh8+ Bf8 8. Qxh5 >>> 9 8.59 +1 1. Qxf4!! >>> 9 8.98 +3 1. Qxf4!! >>> 9 9.80 +M 1. Qxf4!! >>> 9 46.31 12.35 1. Qxf4 Be5 2. dxe5 Qd8 3. Bxd8 Rexd8 >>> 4. Qf6 Kf8 5. Bxf7 >>> 9-> 46.32 12.35 1. Qxf4 Be5 2. dxe5 Qd8 3. Bxd8 Rexd8 >>> 4. Qf6 Kf8 5. Bxf7 >>> 10 59.13 +1 1. Qxf4!! >>> 10 1:12 +3 1. Qxf4!! >>> 10 1:32 +M 1. Qxf4!! >>> 10 7:05 Mat06 1. Qxf4 Bxf4 2. Rxh5 gxh5 3. Rxh5 Bh6 >>> 4. Rxh6 Qh2+ 5. Kxh2 Kf8 6. Rh8# >>> 10-> 7:05 Mat06 1. Qxf4 Bxf4 2. Rxh5 gxh5 3. Rxh5 Bh6 >>> 4. Rxh6 Qh2+ 5. Kxh2 Kf8 6. Rh8# >>>exit 11 7:30 1/6? 1. Qxf4 >>>White(1): exit >>>analyze.White(1): analyze complete. >>> >>> >>>I'm still not seeing it till ply 12 so mine takes even longer! >>> >>>Andy. >> >>my engine, which has only mate threat extension and a captures only qsearch, >>also takes 12 plies to find the mate. It sees that Qxf4 is winning at ply 9. I >>use R = 2/3. >>132 seconds for a 12 ply search. >> >>setboard 4r1k1/p1qr1p2/2pb1Bp1/1p5p/3P1n1R/1B3P2/PP3PK1/2Q4R w - - bm Qxf4; id >>analyze >> >>1 -101 0 375 g2h2 >>2 -121 0 94 g2h2 e8e2 >>3 -168 1 1238 g2f1 f4d3 c1c2 >>4 -174 1 1589 g2f1 f4e2 c1c2 a7a5 >>5 -159 4 14044 g2f1 e8e2 h1g1 a7a5 g1g3 >>6 -175 15 36735 g2f1 c6c5 d4c5 f4d3 c1h6 d6c5 >>7 -180 48 125259 g2f1 e8e2 c1b1 d6e7 h4f4 c7f4 f1e2 e7f6 >>8 -166 109 269919 g2f1 e8e2 c1b1 e2d2 b1c1 d6b4 h1g1 c7d6 >>9 578 740 2537825 c1f4 d6e7 b3f7 g8f8 f6e5 g6g5 f4f5 c7a5 f5d7 f8f7 h4h5 a5a2 >>10 903 1506 3165852 c1f4 d6e7 h4h5 e7f6 f4f6 c7g3 f2g3 g6h5 f6g6 g8f8 g6c6 d7d4 >>c6b5 >>11 951 3393 8126737 c1f4 d6e7 h4h5 e7f6 f4f6 c7g3 g2g3 g6h5 f6c6 e8e7 >>12 19986 13175 40793708 c1f4 d6e7 h4h5 e7f6 f4f6 c7g3 g2g3 g6h5 h1h5 e8e7 f6h8# >>move c1f4 > >Hmm -- guess I feel heartened that even the great Crafty sees that the >reply to Qxf4 is not Bxf4. Both Be7 and Bxf4 lose in the same amount of ply, so it is probably nothing to worry about--the same score would be backed up.
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