Author: Uri Blass
Date: 01:38:22 12/02/02
Go up one level in this thread
On December 02, 2002 at 04:03:35, David Rasmussen wrote: >On December 01, 2002 at 18:34:09, Roy Eassa wrote: > >> >>OK, I think I see now. A brief analysis: >> >>1.Qe6! >> >> [1.Nd8 h6 2.Ne6 Ne8 3.Qf8+ Kh7 4.Qf4 Qc3 5.Rc1 Qb2 6.Kg2 Nf6 7.Qxb8 Qxc1 >> 8.Qxa7 Nh5 9.Qf7 Qc8 10.Qf5+ Kh8 11.Nxg7 Qxf5 12.Nxf5 Nf4+ 13.Kg3 Ne2+ >> 14.Kg4 Nc3 15.Nxh6 b5 +-] >> >>1...h5 2.Ng5+ Kh8 3.Qf5! Qxa2 >> >> [3...Kg8 4.Re7 Qb4 >> (4...h4 5.Kg2 Qc1 6.h3 Qc5 7.Rxg7+ Kxg7 8.Ne6+ +-) >> 5.Rxa7 Qe1+ 6.Kg2 Qe8 7.Ne6 Nd7 8.Qd5 +-] >> >>4.Re7 Qa3 5.Rf7 Kg8 6.h4! Rf8 >> > >Several times along this analysis, Chezzz finds the right move (although not at >the beginning, in reasonable time). But this move seems to be a key move for >Chezzz. It has a hard time finding Re7. It prefers Qg6 here for a long time. >Maybe if Re7 was more obvious for Chezzz in this position, the solution to the >original position would be easier to find. So I think that this makes a good >test position (at least for amateurs): I am not sure if Re7 is the only winning move > >[D]1r5k/p5p1/1p3n2/5QNp/8/5P2/q4P1P/4R1K1 w - - 0 4 > >Chezzz actually prefers Re6 here, but it seems that this has a lot to do with >hashing. If I search for some time (say, a minute) and stop the search, and then >redo the search (without clearing the hashtable) Re7 is sometimes found >immediately. This sort of behavior I've seen before, and it annoys me. I don't >know if it's a bug or what. I suspect that it is a common hashing/null >move/repetition/whatever problem. > >time nodes depth score pv >00:00:00.14 77kn 06/11/12 -1.465 4. Qe5 Rd8 5. Ne4 Rd5 > 6. Qe6 Nd7 >00:00:00.21 122kn 06/13/13 -1.220 4. Re7 Qa1+ 5. Kg2 Qa3 > 6. Nf7+ Kg8 7. Nh6+ gxh6 > 8. Qxf6 >00:00:00.29 165kn 06/14/14 -1.187 4. Qg6! >00:00:00.40 225kn 06/14/14 -0.425 4. Qg6 h4 5. Re7 Qa1+ > 6. Kg2 h3+ 7. Nxh3 Nd5 >00:00:00.43 234kn 06/14/14 --------------------------------------------------- >00:00:00.54 303kn 07/15/15 -0.205 4. Qg6 h4 5. Re7 Qa1+ > 6. Kg2 h3+ 7. Nxh3 Rg8 > 8. Ng5 >00:00:00.64 337kn 07/15/15 --------------------------------------------------- >00:00:01.06 572kn 08/17/17 +0.000 4. Qg6 h4 5. Re7 Qa1+ > 6. Kg2 h3+ 7. Kxh3 Qf1+ > 8. Kg3 Qg1+ 9. Kh3 Qf1+ >00:00:01.17 625kn 08/17/17 --------------------------------------------------- >00:00:01.68 930kn 09/19/22 +0.000 4. Qg6 h4 5. Re7 Qa1+ > 6. Kg2 h3+ 7. Kxh3 Qf1+ > 8. Kg3 Qg1+ 9. Kh3 Qf1+ >00:00:02.37 1292kn 09/20/22 --------------------------------------------------- >00:00:03.62 2066kn 10/22/23 +0.000 4. Qg6 h4 5. Re7 Qa1+ > 6. Kg2 h3+ 7. Kxh3 Qf1+ > 8. Kg3 Qg1+ 9. Kh3 Qf1+ >00:00:09.93 5511kn 10/23/24 --------------------------------------------------- >00:00:13.56 7614kn 11/26/26 +0.000 4. Qg6 Qa3 5. Nf7+ Kg8 > 6. Nh6+ Kh8 7. Nf7+ >00:00:43.73 24Mn 11/26/27 +0.333 4. Re6! Movei00_782 shows similiar behaviour depth=11 +0.01 e1e6 Nodes: 9412638 NPS: 185873 Time: 00:00:50.64 depth=11 +0.30 e1e6 Nodes: 11266209 NPS: 182655 Time: 00:01:01.68 >00:01:50.70 58Mn 11/28/28 +1.160 4. Re6 Kg8 5. Kg2 Qd5 > 6. Rxf6 Qxf5 7. Rxf5 a6 depth=11 +2.58 e1e6 h8g8 g1g2 a2d5 e6f6 d5f5 f6f5 b8e8 f5d5 g8f8 d5d7 e8e7 Nodes: 23372794 NPS: 181903 Time: 00:02:08.49 > 8. Ne4 h4 9. Re5 >00:01:58.87 63Mn 11/28/28 --------------------------------------------------- depth=11 +2.58 e1e6 h8g8 g1g2 a2d5 e6f6 d5f5 f6f5 b8e8 f5d5 g8f8 d5d7 e8e7 Nodes: 23372794 NPS: 181903 Time: 00:02:08.49 >00:02:22.67 74Mn 12/27/30 +1.085 4. Re6 Kg8 5. Kg2 Qd5 > 6. Rxf6 Qxf5 7. Rxf5 a6 > 8. Ne4 g6 9. Re5 a5 depth=12 +2.59 e1e6 h8g8 g1g2 a2d5 e6f6 d5f5 f6f5 b8d8 g2g3 g7g6 g5e6 g6f5 e6d8 Nodes: 34692304 NPS: 182696 Time: 00:03:09.89 >00:02:33.21 80Mn 12/27/30 --------------------------------------------------- depth=12 +2.59 e1e6 h8g8 g1g2 a2d5 e6f6 d5f5 f6f5 b8d8 g2g3 g7g6 g5e6 g6f5 e6d8 Nodes: 88632716 NPS: 183398 Time: 00:08:03.28 >force:44.06 86Mn 13/29/30 1/41 4. Re6 depth=13 +2.69 e1e6 h8g8 g1g2 a2d5 e6f6 d5f5 f6f5 b8d8 g2g3 g7g6 f5f6 g8g7 f6f7 g7h6 g3f4 Nodes: 111383437 NPS: 183901 Time: 00:10:05.67 > > > Time used: 00:02:45.37 > nps: 525234 nodes: 86863298 Q-nodes: 2538298 (2%) > move order: 95% > hash probes: 20649151 hash hits: 6194318 (29%) hash usage: 95% > pawn hash probes: 41198561 pawn hash hits: 41190951 (99%) > EGTB probes: 22 > >Chezzz also have problems finding 6. h4! quickly : Again same for Movei that likes Kg2 at small depthes > >time nodes depth score pv >00:00:00.14 72kn 06/13/13 +0.710 6. Kg2 Qa5 7. Rxf6 Qxf5 > 8. Rxf5 a5 >00:00:00.21 93kn 06/14/14 --------------------------------------------------- >00:00:00.22 98kn 07/10/10 +1.043 6. Kg2! >00:00:00.25 117kn 07/15/15 +1.085 6. Kg2 Qa5 7. Rxf6 Qxf5 > 8. Rxf5 a6 9. Rf7 >00:00:00.33 144kn 07/15/15 --------------------------------------------------- >00:00:00.36 159kn 08/17/18 +1.010 6. Kg2 Qa5 7. Rxf6 Qxf5 > 8. Rxf5 a6 9. Rf7 a5 >00:00:00.50 211kn 08/17/18 --------------------------------------------------- >00:00:00.55 243kn 09/15/16 +1.343 6. Kg2! >00:00:00.96 510kn 09/20/20 +1.580 6. Kg2 Qa5 7. Rb7 Qxf5 > 8. Rxb8+ Ne8 9. Rxe8+ Qf8 > 10. Rxf8+ Kxf8 11. Ne6+ Kf7 > 12. Nf4 g6 >00:00:02.16 1158kn 09/20/23 --------------------------------------------------- >00:00:02.83 1589kn 10/22/22 +1.605 6. Kg2 Qa5 7. Rb7 Qxf5 > 8. Rxb8+ Ne8 9. Rxe8+ Qf8 > 10. Rxf8+ Kxf8 11. Ne6+ Kf7 > 12. Nf4 h4 13. Nd5 >00:00:03.80 2054kn 10/22/23 --------------------------------------------------- >00:00:04.69 2582kn 11/24/24 +1.450 6. Kg2 Qa5 7. Rb7 Qxf5 > 8. Rxb8+ Ne8 9. Rxe8+ Qf8 > 10. Rxf8+ Kxf8 11. Ne6+ Kf7 > 12. Nf4 a5 13. Nxh5 b5 >00:00:25.42 14Mn 11/25/28 +1.650 6. Rc7 Qd6 7. Rxa7 Qd1+ > 8. Kg2 h4 9. Qg6 h3+ > 10. Nxh3 Ne8 11. Qf7+ Kh7 > 12. Ng5+ Kh6 13. Ne4 >00:00:32.52 18Mn 11/26/28 +1.938 6. h4! depth=10 +2.60 h2h4 Nodes: 15471650 NPS: 180595 Time: 00:01:25.67 depth=10 +2.89 h2h4 Nodes: 18853881 NPS: 181130 Time: 00:01:44.09 >00:02:18.96 71Mn 11/28/28 +3.340 6. h4 Rf8 7. Rxf6 Rxf6 > 8. Qh7+ Kf8 9. Qh8+ Ke7 > 10. Qxg7+ Kd6 11. Qxf6+ Kd5 > 12. Qd8+ Kc4 13. Qg8+ Kb4 > 14. Qf8+ Ka4 15. Qe8+ b5 > 16. Qxh5 >00:02:19.06 71Mn 11/28/28 --------------------------------------------------- depth=10 +3.51 h2h4 b8f8 f7f6 f8f6 f5h7 g8f8 h7h8 f8e7 h8g7 e7d8 g7f6 a3e7 f6g6 e7e8 g6g7 Nodes: 33853713 NPS: 182146 Time: 00:03:05.86 Uri
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