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Subject: Re: An unexplainable blunder

Author: John Merlino

Date: 22:01:53 07/25/03

Go up one level in this thread


On July 25, 2003 at 20:33:49, Omid David Tabibi wrote:

>>[Event "7"]
>>[Site "S"]
>>[Date "2008.07.23"]
>>[Round "12"]
>>[White "Junior 8"]
>>[Black "Ktulu 3.7"]
>>[Result "0-1"]
>>[ECO "D12"]
>>[PlyCount "110"]
>>[EventDate "2008.07.17"]
>>[Source "a"]
>>
>>1. c4 {0} 1... c6 {0} 2. Nf3 {0} 2... d5 {0} 3. e3 {0} 3... Nf6 {0} 4. d4 {0}
>>4... Bf5 {0} 5. Qb3 {0} 5... Qc7 {0} 6. cxd5 {0.11/17 224} 6... cxd5 {0} 7. Nc3
>>{0} 7... e6 {0} 8. Bd2 {0} 8... Nc6 {0} 9. Be2 {0} 9... Be7 {0} 10. O-O {0}
>>10... O-O {0} 11. Rfc1 {0} 11... Nd7 {-0.15/12 158} 12. a3 {-0.35/17 96} 12...
>>Rac8 {(a6) -0.19/12 101} 13. Na2 {(Qd1) -0.29/17 99} 13... Bd6 {
>>(Nf6) -0.20/11 98} 14. Bb4 {(Nc3) -0.20/17 85} 14... Qb6 {-0.27/12 96} 15. Nc3
>>{(Nh4) -0.20/16 214} 15... Bxb4 {-0.66/11 93} 16. axb4 {-0.31/17 130} 16...
>>Nxb4 {-0.67/13 90} 17. Na4 {(Qa4) -0.28/17 118} 17... Rxc1+ {-0.57/13 88} 18.
>>Rxc1 {-0.35/18 115} 18... Qa5 {-0.65/14 85} 19. Bf1 {-0.23/18 76} 19... a6 {
>>(b6) -0.57/13 83} 20. Nc5 {-0.16/18 94} 20... Nxc5 {-0.54/15 81} 21. Rxc5 {
>>-0.23/17 27} 21... Qb6 {-0.53/14 78} 22. Ne5 {-0.18/19 101} 22... Rd8 {
>>-0.51/15 76} 23. Bd3 {-0.18/17 55} 23... Bxd3 {-0.21/15 74} 24. Nxd3 {
>>-0.02/17 20} 24... a5 {-0.25/15 72} 25. Nxb4 {-0.02/19 51} 25... axb4 {
>>-0.21/15 70} 26. h3 {0.03/20 69} 26... f6 {(h5) -0.18/15 68} 27. Qa4 {
>>0.22/19 41} 27... Kf7 {(h6) -0.16/14 66} 28. g4 {(Qc2) 0.26/18 56} 28... Qd6 {
>>-0.16/13 64} 29. Rb5 {(Kg2) 0.26/18 54} 29... Rd7 {-0.15/14 63} 30. Rxb4 {
>>(Qxb4) 0.27/20 83} 30... Rc7 {-0.08/14 61} 31. Qa5 {(Qb3) 0.24/19 99} 31... g5
>>{(Qd7) -0.25/12 59} 32. Rb6 {0.70/18 50} 32... Qd7 {(Qf8) -0.14/14 58} 33. Qa8
>>{(Qd2) 0.68/19 36} 33... Kg7 {-0.04/14 56} 34. Kh2 {(Kg2) 0.81/19 59} 34... Qf7
>>{(e5) -0.13/13 54} 35. Kg2 {(Qb8) 0.81/19 46} 35... Rd7 {(Qd7) -0.05/13 53} 36.
>>Qc8 {(f3) 0.94/19 33} 36... Qe7 {(h6) -0.01/13 52} 37. Kg1 {0.81/18 31} 37...
>>Qf7 {(e5) -0.04/13 50} 38. Qb8 {0.85/19 63} 38... Qe7 {-0.13/14 49} 39. Kg2 {
>>0.94/19 53} 39... e5 {(Qf7) -0.03/14 47} 40. dxe5 {0.53/17 46} 40... fxe5 {
>>0.00/15 46} 41. Rb5 {0.66/17 82} 41... e4 {(h6) 0.00/15 45} 42. Qa7 {0.93/17 26
>>} 42... Kf7 {(Qf7) 0.01/1 44} 43. Qd4 {1.18/18 71} 43... Qf6 {(Ke6) 0.49/16 142
>>} 44. Rxb7 {1.78/16 25} 44... Qxd4 {0.08/19 38} 45. Rxd7+ {0.45/20 42} 45...
>>Ke8 {0.08/20 37} 46. exd4 {0.36/20 31} 46... Kxd7 {0.01/1 36} 47. h4 {
>>0.20/26 26} 47... h6 {(gxh4) 0.04/19 35} 48. h5 {(Kg3) 0.00/25 35} 48... Kc6 {
>>0.00/23 34}
>
>[D]8/8/2k4p/3p2pP/3Pp1P1/8/1P3PK1/8 w - - 0 49
>
>>49. Kg3
>
>??
>How could Junior possibly play this move? Any engine I tried refutes 49. Kg3 in
>less than a second... The obvious move 49. f3 reaches an easy draw.

The loss might be tough to see at faster time controls, as the loss of the pawn
is 20 plies away.

Chessmaster 9000, for example, on a P4-2.44, fails low on Kg3 in about 15
seconds, but needs 1:11 to show a losing eval. It then needs to go to almost two
full minutes of total search before it switches to Kf1 with a drawing score:

Time	Depth	Score	Positions	Moves
0:00	9/13	0.32	82071		49.Kg3 Kb5 50.f4 exf3ep 51.Kxf3
					Kc4 52.Ke3 Kb3 53.Ke2 Kxb2 54.Kd2
					Kb3 55.Kd3 Kb4
0:00	10/14	0.32	139009		49.Kg3 Kb5 50.f4 exf3ep 51.Kxf3
					Kc4 52.Ke3 Kb3 53.Ke2 Kxb2 54.Kd2
					Kb3 55.Kd3 Kb4
0:00	11/15	0.08	247311		49.Kg3 Kb5 50.f4 exf3ep 51.Kxf3
					Kc4 52.Ke3 Kb3 53.Ke2 Kxb2 54.Kd2
					Kb3 55.Kd3 Kb4 56.Ke3 Kc4
0:01	12/16	0.08	419177		49.Kg3 Kb5 50.f4 exf3ep 51.Kxf3
					Kc4 52.Ke3 Kb3 53.Ke2 Kxb2 54.Kd2
					Kb3 55.Kd3 Kb4 56.Ke3 Kc4
0:02	13/17	0.04	750094		49.Kg3 Kb5 50.f4 exf3ep 51.Kxf3
					Kc4 52.Ke3 Kb3 53.Ke2 Kxb2 54.Kd2
					Kb3 55.Kd3 Kb4 56.Ke2 Kc4 57.Ke3
0:05	14/18	0.00	1357606		49.Kg3 Kb5 50.f4 exf3ep 51.Kxf3
					Kc4 52.Ke3 Kb3 53.Ke2 Kxb2 54.Kd2
					Kb3 55.Kd3 Kb4 56.Kd2 Kb3
0:09	15/19	0.00	2510018		49.Kg3 Kb5 50.f4 exf3ep 51.Kxf3
					Kc4 52.Ke3 Kb3 53.Ke2 Kxb2 54.Kd2
					Kb3 55.Kd3 Kb4 56.Kd2 Kb5 57.Kc3
					Ka4 58.Kd2 Kb5
1:11	16/20	-2.37	15935155	49.Kg3 Kb5 50.f4 exf3ep 51.Kxf3
					Kc4 52.Ke3 Kb3 53.Ke2 Kxb2 54.Kd2
					Kb3 55.Kd3 Kb4 56.Ke3 Kc4 57.Ke2
					Kxd4 58.Kd2 Ke4 59.Kc3
1:57	16/20	0.00	26201737	49.Kf1 Kb5 50.Ke2 Kc4 51.Kd1 Kxd4
					52.Ke2 Ke5 53.f3 exf3+ 54.Kxf3
					Kd4 55.Ke2 Ke4 56.Kd2 Kd4 57.Ke2
1:59	17/21	0.00	26834298	49.Kf1 Kb5 50.Ke2 Kc4 51.Kd1 Kxd4
					52.Ke2 Ke5 53.f3 exf3+ 54.Kxf3
					Kd4 55.Ke2 Ke4 56.Kd2 Kd4 57.Ke2
2:07	18/22	0.00	28939522	49.Kf1 Kb5 50.Ke2 Kc4 51.Kd1 Kxd4
					52.Ke2 Ke5 53.f3 exf3+ 54.Kxf3
					Kd4 55.Ke2 Ke4 56.Kd2 Kd4 57.Ke2
2:31	19/23	0.00	34612451	49.Kf1 Kb5 50.Ke2 Kc4 51.Kd1 Kxd4
					52.Ke2 Ke5 53.f3 exf3+ 54.Kxf3
					Kd4 55.Ke2 Ke4 56.Kd2 Kd4 57.Ke2

jm



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