Author: Richard Pijl
Date: 09:31:50 11/18/02
Go up one level in this thread
On November 18, 2002 at 08:11:04, Jim Monaghan wrote: >Milan posted an interesting game in the WB forum. > >AMD XP 1600+ >Single 1700 MHz >32 MB Hash >ponder off >Deep Fritz 7 GUI >Time 60/60' + 20/20' + 10' >Shredder6.ctg for all / read only. > > >The following position shows an interesting evaluation error. > [D] 4r2k/ppn1r2p/2pqn1p1/3bRp2/3P4/P1N2P1P/1PQ2BP1/2R2BK1 b - - > > >The setting is a fairly complex, crowded middlegame with perhaps roughly level >(that is not to say drawish) chances. The King has slightly the worse pawn >structure being hampered somewhat by an isolated d-pawn. In compensation, he has >the two bishops which if the position opens up could become very powerful. >Black's pawn formation is more compact (only two pawn islands) yet his kingside >is rather airy and he is somewhat weak on the dark squares. Most of his pawns >have moved to light squares and he is lacking his KB. A factor which could >become deadly should the position open up. I don't see an active plan for him. >If he advances his king-side pawns to attack the White castled position, the >resulting open lines and weak dark squares would probably rebound on him. In >view of this, Black should simply hold pat and play a waiting game. > >Instead, Shredder uncorks 31... Bxf3?! This leads to an unbalanced material >situation with blurred positional values. The move is a pretty idea with a >forced variation that leads to this position: > [D] 4n2k/pp5p/2pq2p1/5p2/8/P1N2P1P/1PR2B2/5BK1 b - - > >Black has a Q+N+6Ps vs R+2Bs+N+4Ps. The difference is Q+Ps vs R+2Bs, statically >that's 13=13. But, White's two bishops acting in concert in an open position is >certainly worth more than "6". Black's pawns are better. White's pawns are >broken up on the king-side, but are they really weak? Black has hardly anything >left to attack them with. I would think it's only a matter of time, before White >unravels his temporarily awkwardly placed pieces and gets them co-ordinated to >penetrate the Black position. This is exactly what happened in the game. > >At 14 ply and over 20 minutes later, Shredder still wants to go into the line. > > 7.01 0:01 +0.61 31...c5 32.Nxd5 Nxd5 33.Ree1 cxd4 34.Bb5 Rd8 35.Qd3 Qf4 >(279.488) 226.8 > 8.01 0:02 +0.36-- 31...c5 32.Nxd5 Nxd5 33.Bb5 Nxd4 34.Rxe7 Qxe7 35.Bxd4+ >cxd4 (544.711) 236.4 > 8.01 0:03 +0.29 31...c5 32.Nxd5 Nxd5 33.Bb5 Nxd4 34.Rxe7 Rxe7 35.Qxc5 Nxb5 >36.Bd4+ Kg8 37.Qxb5 (736.657) 241.1 > 9.01 0:06 +0.04-- 31...c5 32.Rxd5 Nxd5 33.dxc5 Qd8 34.Rd1 Kg8 35.Nxd5 Rc7 >36.Nxc7 Qxc7 (1.689.322) 252.5 > 9.01 0:07 -0.46-- 31...c5 32.Rxd5 Nxd5 33.dxc5 Qd8 34.Rd1 Kg8 35.Nxd5 Nc7 >36.Nxe7+ Kg7 37.Rxd8 (1.938.159) 256.3 > 9.01 0:09 -1.52 31...c5 32.Rxd5 Nxd5 33.dxc5 Qd8 34.Rd1 Rd7 35.Bb5 Nef4 >36.Bg3 Ree7 37.Qb3 Nh5 38.Nxd5 Nxg3 (2.521.639) 257.9 > 9.02 0:10 -1.51++ 31...Nf4 32.Qd2 Nxh3+ 33.gxh3 Bxf3 34.Rxe7 Qxe7 35.h4 >(2.688.863) 256.9 > 9.02 0:10 -1.16++ 31...Nf4 32.Qd2 Nxh3+ 33.gxh3 Bxf3 34.Rxe7 Rxe7 35.d5 >(2.745.905) 256.7 > 9.02 0:14 +0.01 31...Nf4 32.Qd2 Nh5 33.Nxd5 Nxd5 34.Rce1 Nhf4 35.Rxe7 Rxe7 >36.Bc4 Kg7 (3.712.586) 253.2 > 9.04 0:16 +0.02++ 31...h6 32.Qd2 Kh7 33.Rce1 a6 34.Nxd5 Nxd5 35.Kh1 Qd8 >(4.213.439) 249.9 > 9.04 0:19 +0.15 31...h6 32.Kh1 a6 33.Bd3 Nf4 34.Nxd5 Ncxd5 35.Rxe7 Rxe7 >36.Bh4 g5 (4.810.289) 248.6 > 10.01 0:32 +0.05 31...h6 32.Kh1 Kh7 33.Rce1 b6 34.Bh4 Rd7 35.Nxd5 Nxd5 >36.Qd2 (7.968.004) 244.9 > 11.01 0:59 -0.08 31...h6 32.Kh1 Kg8 33.Qa4 a6 34.Bh4 g5 35.Bf2 (14.366.223) >241.9 > 11.09 1:41 -0.07++ 31...Bxf3 32.gxf3 Nxd4 33.Rxe7 Nxc2 34.Rxe8+ Nxe8 35.Rxc2 >a6 36.Ne4 Qf4 37.Bc4 Qxf3 (24.558.569) 242.3 > 11.09 1:47 +0.09 31...Bxf3 32.gxf3 Nxd4 33.Rxe7 Nxc2 34.Rxe8+ Nxe8 35.Rxc2 >b6 36.Kg2 g5 37.Be3 Qe7 38.Bd4+ (26.158.540) 243.2 > 12.01 2:22 -0.01 31...Bxf3 32.gxf3 Nxd4 33.Rxe7 Nxc2 34.Rxe8+ Nxe8 35.Rxc2 >a5 36.Re2 Nf6 37.Bg2 Kg7 (35.253.501) 247.0 > 13.01 5:21 -0.02 31...Bxf3 32.gxf3 Nxd4 33.Rxe7 Nxc2 34.Rxe8+ Nxe8 35.Rxc2 >b6 36.Kg2 Kg7 37.Bc4 Qxa3 (80.501.451) 250.3 > 14.01 10:47 -0.10 31...Bxf3 32.gxf3 Nxd4 33.Rxe7 Nxc2 34.Rxe8+ Nxe8 35.Rxc2 >b6 36.Kg2 Nf6 37.Bc4 Nh5 38.Ne2 c5 39.Be3 (167.491.119) 258.8 >best move: Bd5xf3 time: 21:24.978 min n/s: 252.647 CPU 98.8% nodes: >324.643.725 > >How do other engines fair? Baron 0.99.3 on slow hardware (Mobile Pentium II 500Mhz) selects a6 with a slightly negative score even after 1 hour: ply time nodes score pv 5( 6)& 0 21133 9 f5f4 c2a4 a7a6 f1d3 h8g8 5( 8)& 0 52820 12 a7a6 c2d1 h8g8 f1d3 f5f4 5( 8). 0 67802 12 a7a6 c2d1 h8g8 f1d3 f5f4 6(10)& 1 139412 -1 a7a6 g1h1 f5f4 f1d3 6(10)& 1 215111 1 c6c5 c3d5 c7d5 f1c4 d5c7 c4e6 6(10). 2 246978 1 c6c5 c3d5 c7d5 f1c4 d5c7 c4e6 7(10)& 3 335026 1 c6c5 c3d5 c7d5 f1c4 d5c7 c4e6 c7e6 7(12). 6 680334 1 c6c5 c3d5 c7d5 f1c4 d5c7 c4e6 c7e6 8(12)& 9 1018036 10 c6c5 c3d5 c7d5 f1b5 e6d4 e5e7 e8e7 c2c5 8(13). 11 1282422 10 c6c5 c3d5 c7d5 f1b5 e6d4 e5e7 e8e7 c2c5 9(14)& 20 2378549 -17 h8g8 c2a4 a7a6 c1e1 b7b5 a4a5 9(14)& 55 5960138 -16 e6f4 c2a4 a7a6 c1e1 d6f6 e5e7 e8e7 e1e7 9(15). 90 9839455 -16 e6f4 c2a4 a7a6 c1e1 d6f6 e5e7 e8e7 e1e7 10(16)& 148 16232212 -25 e6f4 c1e1 d6f6 e5e7 e8e7 e1e7 f6e7 c2a4 a7a6 a4a5 10(16)& 185 20634985 -22 a7a6 c1e1 f5f4 f1d3 d6d7 c3a4 h8g8 a4b6 d7d8 b2b3 10(17). 318 35303939 -22 a7a6 c1e1 f5f4 f1d3 d6d7 c3a4 h8g8 a4b6 d7d8 b2b3 11(17)& 394 42925321 -20 a7a6 c1e1 h8g8 c2a4 f5f4 f2h4 e7d7 f1d3 d5b3 11(18). 908 98808383 -20 a7a6 c1e1 h8g8 c2a4 f5f4 f2h4 e7d7 f1d3 d5b3 12(18)& 1111 119629200 -29 a7a6 c1e1 h8g8 c2a4 f5f4 f2h4 e7d7 h4g5 b7b5 12(20). 3594 382840776 -29 a7a6 c1e1 h8g8 c2a4 f5f4 f2h4 e7d7 h4g5 b7b5 After Bxf3 (and a clean hash :-) ) Baron scores a nice plus for white: ply time nodes score pv 5( 9)& 0 27302 91 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 5( 9). 0 48859 91 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 6(11)& 0 58418 91 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 c1c2 6(11). 0 112835 91 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 c1c2 7(12)& 1 142934 85 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 c1c2 a7a5 7(12). 2 295983 85 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 c1c2 a7a5 8(14)& 3 417260 114 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 c1c2 a7a5 f2e3 8(14). 8 961608 114 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 c1c2 a7a5 f2e3 9(15)& 12 1441306 102 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 c1c2 b7b6 f2e3 d6g3 9(15). 25 3038760 102 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 c1c2 b7b6 f2e3 d6g3 10(17)& 38 4676275 114 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 c1c2 b7b6 c2e2 e8c7 10(17). 73 8906561 114 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 c1c2 b7b6 c2e2 e8c7 11(18)& 100 12598314 98 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 c1c2 b7b6 c2e2 e8f6 e2e1 f6d5 11(18). 233 28709885 98 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 c1c2 b7b6 12(19)& 316 39060252 112 g2f3 e6d4 e5e7 d4c2 e7e8 c7e8 c1c2 b7b6 g1g2 e8f6 f1c4 Finally the position after the capture moves: ply time nodes score pv 5( 8)& 0 6620 -98 b7b6 c2e2 e8c7 e2e1 c7d5 5( 8). 0 11260 -98 b7b6 c2e2 e8c7 e2e1 c7d5 6(10)& 0 29820 -109 b7b6 g1g2 e8f6 f1c4 6(11). 0 38110 -109 b7b6 g1g2 e8f6 f1c4 7(11)& 0 59571 -106 b7b6 g1g2 e8f6 f1c4 d6f4 b2b3 f4d6 7(12). 0 107248 -106 b7b6 g1g2 e8f6 f1c4 d6f4 b2b3 f4d6 8(13)& 1 262227 -113 b7b6 g1g2 e8f6 c2e2 f5f4 b2b4 a7a5 e2b2 8(13). 2 405627 -113 b7b6 g1g2 e8f6 c2e2 f5f4 b2b4 a7a5 e2b2 9(15)& 6 787960 -105 b7b6 g1g2 e8f6 c2e2 f5f4 b2b4 g6g5 e2e1 d6d2 9(15). 9 1232084 -105 b7b6 g1g2 e8f6 c2e2 f5f4 b2b4 g6g5 e2e1 d6d2 10(16)& 22 3095210 -112 b7b6 g1g2 e8f6 c2e2 d6d7 f2g3 f6d5 c3d5 c6d5 e2e1 10(16). 36 5142233 -112 b7b6 g1g2 e8f6 c2e2 d6d7 f2g3 f6d5 c3d5 c6d5 e2e1 11(17)& 64 8983748 -130 b7b6 c2c1 d6d2 c1e1 e8f6 e1d1 d2f4 f2d4 11(18). 193 25383469 -130 b7b6 c2c1 d6d2 c1e1 e8f6 e1d1 d2f4 f2d4 12(19)& 252 33620761 -134 b7b6 c2c1 e8f6 c1d1 d6f4 g1g2 f4g5 g2h2 g5f4 f2g3 f4e3 d1d3 e3c5 12(19). 845 108961260 -134 b7b6 c2c1 e8f6 c1d1 d6f4 g1g2 f4g5 g2h2 g5f4 f2g3 f4e3 d1d3 13(20)& 1375 179182581 -112 b7b6 g1g2 e8f6 f1a6 h8g7 c3e2 f6d5 b2b4 g7f7 e2d4 d5f4 13(21). 1967 254891377 -112 b7b6 g1g2 e8f6 f1a6 h8g7 c3e2 f6d5 b2b4 g7f7 e2d4 d5f4 Richard.
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.