Author: Robert Hyatt
Date: 13:34:39 09/18/01
Go up one level in this thread
On September 18, 2001 at 13:46:58, Dann Corbit wrote: >On September 18, 2001 at 13:02:02, Ed Schröder wrote: > >>On September 18, 2001 at 12:22:20, Robert Hyatt wrote: >> >>>On September 18, 2001 at 10:53:39, Uri Blass wrote: >>> >>>>On September 18, 2001 at 10:45:15, José Carlos wrote: >>>> >>>>>On September 18, 2001 at 09:56:32, Ed Schröder wrote: >>>>> >>>>>>On September 18, 2001 at 09:40:26, Eduard Nemeth wrote: >>>>>> >>>>>>>First the game: >>>>>>> >>>>>>>[Event "TCh-YUG Herceg Novi YUG"] >>>>>>>[Site "?"] >>>>>>>[Date "2001.??.??"] >>>>>>>[Round "?"] >>>>>>>[White "Vukic,M"] >>>>>>>[Black "Marinkovic,I"] >>>>>>>[WhiteElo "2470"] >>>>>>>[BlackElo "2440"] >>>>>>>[ECO "A30"] >>>>>>>[Result "1-0"] >>>>>>> >>>>>>>1. Nf3 Nf6 2. g3 b6 3. Bg2 Bb7 4. O-O g6 5. c4 c5 6. Nc3 >>>>>>>Bg7 7. d4 cxd4 8. Qxd4 d6 9. Be3 Nbd7 10. Rac1 Rc8 11. b3 >>>>>>>O-O 12. Qd2 Nc5 13. Rfd1 Nce4 14. Nxe4 Nxe4 15. Qe1 Qd7 >>>>>>>16. Nd4 Nf6 17. Nf3 Ne4 18. Qb4 Nc3 19. Rd2 Ne4 20. Rd3 Nc5 >>>>>>>21. Rdd1 Rfd8 22. Ne1 h5 23. Bxc5 Rxc5 24. Nd3 Bxg2 >>>>>>>25. Kxg2 Qb7+ 26. f3 Rc7 27. Nf2 Rdc8 28. Qd2 b5 29. cxb5 >>>>>>>Qxb5 30. Kf1 Bc3 31. Qd3 Qa5 32. Rc2 Bf6 33. Rdc1 Rxc2 >>>>>>>34. Rxc2 Rxc2 35. Qxc2 d5 36. e3 Kg7 37. Nd3 e6 38. Ke2 Qa3 >>>>>>>39. f4 Kg8 40. h3 Kg7 41. Kf3 Qd6 42. g4 hxg4+ 43. hxg4 e5 >>>>>>>44. fxe5 Bxe5 45. Nxe5 Qxe5 46. Qc5 Qf6+ 47. Kg3 Qe5+ >>>>>>>48. Kh3 a6 49. Qd4 Kf6 50. b4 Ke6 51. a4 Qc7 52. g5 Qc2 >>>>>>>53. Qf6+ Kd7 54. Qxf7+ Kd6 55. Qf6+ Kd7 56. Qd4 Ke6 57. Kg3 >>>>>>>Qb1 58. Qb6+ Ke7 59. Qb7+ Kf8 60. Qxd5 Qxb4 61. Qd8+ Kg7 >>>>>>>62. Qd4+ 1-0 >>>>>>> >>>>>>>Position after move 61. Kg7: >>>>>>> >>>>>>>[D]3Q4/6k1/p5p1/6P1/Pq6/4P1K1/8/8 w - - >>>>>>> >>>>>>>After 62. Qf6+ is the win not easy. But after 62. Qd4+ is the game easy to win, >>>>>>>and the game end! For any programs ist the move Qd4+ not easy to find. >>>>>>> >>>>>>>:-( >>>>>> >>>>>> >>>>>>I am sure all Rebel programs find this instantly. A simple chess rule says: >>>>>>"one pawn up in a pawn ending wins". >>>>>> >>>>>>Ed >>>>> >>>>> Are you serious Ed? In this position, it's a clear win, but in most pawn >>>>>endgames, you have to calculate a lot, or otherwise know some rules (which names >>>>>I don't know how to translate from spanish to english) to figure if it's a win >>>>>or not. >>>>> >>>>> Maybe you were simply joking, and I didn't catch it... :) >>>> >>>>In most pawn endgames one pawn advantage is enough to win the game. >>>>It is not something that always happens but computer can safely evaluate >>>>+2 for positions with one pawn advnatage if they do not see a positional >>>>advantage for the side that has less pawns. >>>> >>>>Uri >>> >>> >>>I believe that if humans discover this "rule" in Rebel, it will die a slow >>>and painful death on ICC. I can create _many_ positions where the rule is >>>wrong. And if I can do it, GMs will do it. Happened to me many times. I >>>was burned by going into simple king and pawn endings where I was a pawn up, >>>but my opponent had a distant majority. And he would win. And win. >> >> >>The rule is valid for 90% of all positions and if not search will handle >>the remaining 10% close to zero. I don't give a +5 score for being a pawn >>up in a pawn ending but a reasonable score update enough to force a >>knight/bishop/rook/queen ending to a won pawn ending or to avoid to enter >>a lost pawn ending position. The rule in Rebel is there for more than 10-12 >>years and in that time I have seen only one exception. > >It certainly seems like a very valuable addition to include before any result >can be born out by search. In other words, of all positions seem about equal, a >bonus for an extra pawn seems to be a pretty good idea. If there is some >problem down the line, it will be born out by search (if the time left is long >enough) but if you have to guess -- it seems much better to me to guess for the >better formation. Notice there is _already_ a "bonus" here. Namely the extra pawn.
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.