Test position from 2006

[kgburcham]

19.Nxf7

[D] r1bq1r2/pp1n1p1k/6pN/1N1p2P1/3Qn3/4P3/PP3P1P/R3KBR1 w Q -

[jdart]

I let Toga search this for a while but at ply 15 it's still liking Nxf7 and O-O-O about equally.

What is the source for this? Was it a human or computer game?

--Jon

[kgburcham]

[Event "26th Dutch CC"]
[Site "Leiden NED"]
[Date "2006.11.04"]
[Round "05"]
[Result "1-0"]
[White "Rybka (Computer)"]
[Black "Fruit (Computer)"]
[ECO "D45"]

1.Nf3 Nf6 2.c4 e6 3.Nc3 d5 4.d4 c6 5.e3 Nbd7 6.Qc2 Bd6 7.g4 h6
8.Bd2 Qe7 9.Rg1 e5 10.cxd5 cxd5 11.Nb5 O-O 12.Nh4 Bb4 13.Nf5
Bxd2+ 14.Qxd2 Qd8 15.Qb4 exd4 16.Qxd4 g6 17.Nxh6+ Kh7 18.g5
Ne4 19.Nxf7 Rxf7 20.Rg4 Ndf6 21.Rh4+ Kg8 22.gxf6 Bf5 23.Bd3
Qxf6 24.Qxf6 Rxf6 25.Nc7 Rd8 26.Nxd5 Rxd5 27.Bc4 Rfd6 28.Rd1
Nf6 29.Bxd5+ Rxd5 30.Rxd5 Nxd5 31.Ra4 a6 32.e4 Bd7 33.Rd4 Nb6
34.Rd6 Bc6 35.Rxg6+ Kf7 36.Rg4 Nc4 37.f3 Nxb2 38.h4 Nd3+
39.Kd2 Ne5 40.Rg3 Kf8 41.h5 Nf7 42.Ke3 Be8 43.f4 Nh6 44.f5
Bxh5 45.Rh3 Nxf5+ 46.exf5 Bf7 47.a4 b5 48.a5 Kg7 49.Rh4 1-0

[jdart]

I gave Arasan 10.4 about 45min/move on a quad and it considers Nxf7 best but other moves are close, so this might not be a good test:

C:\chess\temp>\arasan\10.4\win32\release\arasanx -H 256000 -c 4
Arasan 10.4 (SMP build) Copyright 1994-2008 by Jon Dart
test nf7.epd 2500 -N 3
Using book file book.bin
found 5-man tablebases in directory c:\chess\tb
"Rybka-Fruit, 26th Dutch CC, Leiden 2006" bm Nxf7
result: Nxf7 2500 seconds. score: +1.50 5295911000 nodes. ++ corre
ct
Nxf7 Rxf7 Rg4 Ndf6 Rh4+ Kg8 gxf6 Qxf6 Qxf6 Nxf6 Nd6 Rc7 Rf4 Nh5 Rd4 Be6 Bd3 Kh7

result(2): h4 2500 seconds. score: +1.38 5017853503 nodes.
** error
h4 Nb8 Nc3 Nc6 Qxd5 Nxc3 Qxd8 Rxd8 bxc3 Be6 e4 Ne5 Be2 Rac8 f4 Nd3+ Bxd3 Rxd3
result(3): O-O-O 2500 seconds. score: +1.31 5347358072 nodes.
** error
O-O-O Ndc5 h4 Bd7 f3 Bxb5 Bxb5 Qa5 fxe4 Qxa2 Qxd5 Nb3+ Kc2 Rac8+ Bc4 Na5 Nxf7 Nx
c4

solution times:
0 1 2 3 4 5 6 7 8 9

0 | 909.78 *** ***