Author: Rob Shultz
Date: 13:12:35 12/22/00
Go up one level in this thread
On December 22, 2000 at 15:52:19, Ernst A. Heinz wrote: >>On December 22, 2000 at 14:45:03, Ernst A. Heinz wrote: >> >>>>Did you look at what happens if you play a4? Your kingside gets totally >>>>shredded, starting with Qxf7+... >>> >>>Yes, true -- but then Black's King is not standing there! >>> >>>It rather seems quite safe on d8 while White's King gets >>>into mighty trouble on d1 after the sequence a4 - Qxf7+ - >>>Kd8 - Qxg7: >>> >>>[d]2rk3r/6Q1/4p3/1pqpP3/p3b1PP/1B6/PPP2R1R/2K5 b - - 0 1 >>> >>>"DarkThought" quickly scores this as substantially positive >>>for Black, locking onto Qe3+ as the best move almost instantly. >>> >>>=Ernst= >> >>I have no doubt that black might actually be winning here. But that wasn't >>the point. You said you picked a4 at depth=10. For that to happen, you have >>to ignore king safety and sit in the middle of the board, with a queen at f7, >>a rook on the open file, the king rook hanging, the king can't move to connect >>the rooks, etc. >> >>IE at 10 ply it is all judgement, not "truth" as the search probably can't see >>the final outcome. > >"DarkThought" gets a fail-low on 0-0 in iteration #10 with the >score dropping from +1.1 in iteration #9 to just +0.39. Then, >it locks onto a4 and shows the correct PV for it already in >iteration #10 (with the white King being driven to d1 where it >is similarly exposed as the black King on d8). > >So, why should that mean to ignore king safety or all the other >evaluation stuff you are talking about above? > >To me, it simply looks like our search picks up the crucial >threats earlier (maybe, by means of more appropriate extensions >in this particular case) -- no more, no less. > >=Ernst= Chess Tiger 13.0 likes Rc7. I ran it on a PII 450 with 48MB hashtable. 00:00:00.8 0.44 6 44059 Qe7 c3 b4 c4 Qd7 Qg5 dxc4 00:00:00.0 0.46 7 91889 Qe7 a3 a4 Ba2 Rc7 c3 Bg6 00:00:02.1 0.12 8 324422 Qe7 a4 b4 h5 Rc7 h6 gxh6 Rxh6 Rxh6 Qxh6 Kd7 00:00:04.0 0.24 8 476754 Qc7 a3 a4 Ba2 Qe7 h5 Rh6 Rf1 00:00:05.0 0.74 8 639803 Rc7 Rh3 Qe7 a4 b4 h5 Qc5 Rh4 00:00:07.2 0.72 9 806572 Rc7 a3 a4 Ba2 b4 axb4 Qxb4 c3 O-O Kd1 00:00:11.2 0.74 10 1290158 Rc7 a3 a4 Ba2 b4 axb4 Qxb4 c3 O-O Kd1 Qc5 00:00:19.1 0.92 11 2291923 Rc7 a3 a4 Ba2 b4 axb4 Qxb4 c3 O-O Kd1 Qc5 Ke2 00:00:43.2 1.40 12 5323176 Rc7 a3 a4 Ba2 b4 axb4 Qxb4 Qe3 O-O Rf1 Rb8 Qa3 Qd4 00:01:30.0 1.12 13 11353422 Rc7 a3 a4 Ba2 b4 axb4 Qxb4 c3 Qe7 Qg5 Qxg5+ hxg5 Rxh2 Rxh2 a3 Rh8+ Kd7 00:03:54.0 1.26 14 30268218 Rc7 a3 a4 Ba2 b4 axb4 Qxb4 Qe3 O-O c3 a3 Kd1 Qe7 Ke1 Rfc8 bxa3 Rxc3 00:14:02.7 1.16 15 117114018 Rc7 a3 a4 Ba2 b4 axb4 Qxb4 Qe3 O-O c3 a3 Kd1 Qe7 Ke1 Rb8 bxa3 Qxa3 Rob
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