Author: Michael Henderson
Date: 07:13:35 09/03/04
Go up one level in this thread
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
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