Author: Stefan Meyer-Kahlen
Date: 13:32:33 05/02/00
Go up one level in this thread
On May 02, 2000 at 11:37:58, Ed Schröder wrote: >On May 02, 2000 at 09:07:42, Stefan Meyer-Kahlen wrote: > >> >>In my set of tactical test positions there is the following example: >> >>[D] 2rqk2r/pb1nbp1p/4p1p1/1B1n4/Np1N4/7Q/PP3PPP/R1B1R1K1 w k – bm Rxe6 >> >>I can’t remember where I have found this position, but the solution is supposed >>to be Rxe6. Until know every version of Shredder has found this move sooner or >>later and kept it as a best move until the end of my test time. >> >>Last night I have tested my latest version and found something interesting. >>Shredder played Rxe6 after a while as usual, but got a terrible fail low for >>that move at ply 11. >> >>So here is my question: >>Is Rxe6 really the best move and I have introduced a bug somewhere in my code or >>is Rxe6 a mistake? I didn’t find an improvement for white after 1. Rxe6 fxe6, >>but this can be due to my limited chess knowledge. >> >>Here is Shredder’s output: >> >> 6.01 0:00.71 -0.23 1.Bh6 a6 2.Bd3 Bf6 3.Nf3 a5 (63.557) 88.3 >> 6 -> 0:01.76 -0.23 1.Bh6 a6 2.Bd3 Bf6 3.Nf3 a5 (159.299) 90.2 >> 7.01 0:02.71 -0.09 1.Bh6 a6 2.Bd3 Bf6 3.Nb3 N5b6 4.Nxb6 Qxb6 >> (240.167) 88.3 >> 7 -> 0:04.90 -0.09 1.Bh6 a6 2.Bd3 Bf6 3.Nb3 N5b6 4.Nxb6 Qxb6 >> (435.029) 88.6 >> 8.01 0:07.96 -0.01 1.Bh6 a6 2.Bf1 N7f6 3.Rad1 Qa5 4.Bg7 Nf4 >> (704.124) 88.3 >> 8 -> 0:10.15 -0.01 1.Bh6 a6 2.Bf1 N7f6 3.Rad1 Qa5 4.Bg7 Nf4 (911.624) 89.7 >> 9.01 0:17.93 -0.17 1.Bh6 a6 2.Be2 Bg5 3.Bf3 Nf4 4.Qg3 Bxh6 5.Bxb7 >> (1.594.580) 88.8 >> 9 -> 0:32.29 -0.17 1.Bh6 a6 2.Be2 Bg5 3.Bf3 Nf4 4.Qg3 Bxh6 5.Bxb7 >> (2.918.536) 90.3 >>10.01 0:42.76 -0.14 1.Bh6 a6 2.Be2 Qa5 3.b3 e5 4.Nf3 e4 5.Nd2 f5 >> (3.876.621) 90.6 >>10.08 2:02.76 -0.13++ 1.Rxe6 fxe6 2.Nxe6 Qa5 3.Bxd7+ Kxd7 4.Nec5+ Ke8 5.Qd7+ >> Kf8 6.Nxb7 (11.210.309) 91.3 >>10.08 2:26.60 +0.22++ 1.Rxe6 fxe6 2.Nxe6 Qa5 3.Bxd7+ Kxd7 4.Nec5+ Ke8 5.Qd7+ >> Kf8 6.Bh6+ Kf7 7.Nxb7 a6 8.Nxa5 Rc1+ 9.Rxc1 >> (13.366.273) 91.1 >>10.08 3:25.78 +0.40 1.Rxe6 Rc7 2.Re2 O-O 3.Bh6 Re8 4.Rae1 a6 5.Bd3 a5 6.b3 >> (18.827.259) 91.4 >>10 -> 3:45.35 +0.40 1.Rxe6 Rc7 2.Re2 O-O 3.Bh6 Re8 4.Rae1 a6 5.Bd3 a5 6.b3 >> (20.541.368) 91.1 >>11.01 5:35.76 +0.15-- 1.Rxe6 fxe6 2.Nxe6 Qa5 3.Bxd7+ Kxd7 4.Nec5+ Ke8 5.Qd7+ >> Kf7 6.Nxb7 Rc7 7.Nd6+ Kg7 8.Ne8+ Rxe8 9.b3 Rxc1+ >> (31.352.209) 93.3 >>11.01 9:18.76 -0.35-- 1.Rxe6 fxe6 2.Nxe6 Qa5 3.Bxd7+ Kxd7 4.Nec5+ Ke8 5.Qd7+ >> Kf7 6.Nxb7 Rc7 7.Nd6+ Kg7 8.Ne8+ Rxe8 9.Qxe8 Nf6 >> 10.Qb8 Bd6 (54.470.299) 97.4 >>11.01 14:41.53 -1.36 1.Rxe6 fxe6 2.Nxe6 Qa5 3.Bxd7+ Kxd7 4.Nec5+ Ke8 5.Qd7+ >> Kf7 6.Nxb7 Rc7 7.Nxa5 Rxd7 8.Nc6 Rc7 9.Nxe7 >> (86.129.099) 97.7 >>11.02 14:52.57 -1.35++ 1.Bh6 a6 2.Be2 Qa5 3.b3 Nf4 4.Bxf4 Bxg2 5.Qxg2 >> (87.133.005) 97.6 >>11.02 15:07.65 -1.00++ 1.Bh6 a6 2.Bxd7+ Qxd7 3.Nxe6 Qxa4 4.Ng7+ Kd8 5.Qd7+ >> Qxd7 (88.458.785) 97.4 >>11.02 16:23.21 -0.10 1.Bh6 a6 2.Bxd7+ Qxd7 3.b3 e5 4.Qxd7+ Kxd7 5.Rxe5 Bf6 >> 6.Rxd5+ Bxd5 7.Nb6+ Kd6 8.Nxc8+ Kd7 9.Re1 >> (95.283.049) 96.9 >> >>(I have formatted it a bit, hopefully it helps...) >> >>Stefan > >Hi Stefan, > >This position was part of Rebel10's anti-GM discussion a few years ago. Rxe6 >maybe is not the best move but it surely can confuse a GM so much he loses >oversight and start to blunder in all the tactical complications. Like Shredder >also Rebel fails low at a certain moment, see below. > >Ed > >PS, on a 128 Mb machine what are the best hash table settings? I use 48 Mb >for the hash table and 16 Mb for the position table but so now and then I >still notice swapping so I wonder. > > >_______________________________________________________________________________ > >00:00:03 7.20 -0.77 1.Rxe6 fxe6 2.Nxe6 Qa5 3.Bxd7+ Kxd7 > 4.Nec5+ Ke8 5.Qd7+ Kf7 6.Qe6+ Kg7 > 7.Nxb7 Qxa4 8.Qxd5 (3) > >00:00:09 8.00 -0.01 1.Rxe6 a6 2.Rxe7+ Nxe7 3.Bxd7+ Qxd7 > 4.Qxd7 Kxd7 5.Nb6 Kc7 6.Nxc8 Rxc8 > 7.Bd2 Nd5 8.Rc1 Kd6 9.Rxc8 Bxc8 (6) > >00:00:22 9.00 0.20 1.Rxe6 a6 2.Bxa6 fxe6 3.Bxb7 Rc4 > 4.Nxe6 Qa5 5.Qf3 (10) > >00:01:03 10.00 0.19 1.Rxe6 Rc7 2.Re2 a6 3.Bd3 Rxc1+ > 4.Rxc1 Nf4 5.Qe3 Nxe2+ 6.Qxe2 Qa5 > 7.b3 (24) > >00:02:00 11.00 -0.32 1.Rxe6 fxe6 2.Nxe6 Qa5 3.Bxd7+ Kxd7 > 4.Nec5+ Ke8 5.Qd7+ Kf7 6.Nxb7 Rc7 > 7.Nd6+ Kg7 8.Ne8+ Rxe8 9.Qxe8 Nf6 > 10.Qb8 Rxc1+ 11.Rxc1 Qxa4 (93) > >00:04:06 12.00 -0.91 1.Rxe6 fxe6 2.Nxe6 Qa5 3.Bxd7+ Kxd7 > 4.Nec5+ Ke8 5.Qd7+ Kf7 6.Nxb7 Rc7 > 7.Nxa5 Rxd7 8.Nc6 Kg7 9.Bd2 (210) > >00:10:00 12.03 -0.85 1.Bd2 a6 2.Bd3 O-O 3.Bh6 Re8 4.Rac1 > Rxc1 5.Rxc1 Bg5 6.Nc6 (297) Hi Ed, thanks for the ínfo. So I will add this position to my antiGM collection :-) You can even increase the eval hash more and usually won't get any swapping. If there is swapping in your config there is something wrong. Thing will get easier with Shredder5, so please be patient... Stefan
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.