Author: Vincent Diepeveen
Date: 07:41:00 03/17/04
Go up one level in this thread
On March 17, 2004 at 09:58:37, martin fierz wrote: >On March 17, 2004 at 08:57:28, Vasik Rajlich wrote: > >>On March 17, 2004 at 08:19:21, Joachim Rang wrote: >> >>>On March 16, 2004 at 18:58:46, Dann Corbit wrote: >>> >>>>See this thread: >>>>http://www.talkchess.com/forums/1/message.html?354948 >>> >>>well after some study with Shredder 8 it is my opinion, that the testposition is >>>wrong in that aspect, that it is not clear whether Rxe6 is the only move to win >>>the game. But I am quite sure, that it is a winning move, but Qh3 dould be >>>winning also (most likely I think). >>> >>>The main variation after Rxe6 is the following one: >>> >>>1.Rxe6 Qxe6 2. Rde1 Qf5 (Qd6 3.Bf4 h5 4. Qxc8 Rxc8 5. Bxd6 Bxd6 6. Bxd5+ +-) 3. >>>Qxf5 gxf5 (all other moves loose instantly) 4. Bxd5+ Kg6 (only move): >>> >>>Now Shredder 8 gives + 2.36 at depth 25. This is not a prove but it seems >>>unlikely that this position is not won for white. >>> >>>As i posted before I get +1.98 wiht a 24ply-search for 1. Qh3 in the >>>startposition, which also seems rather convincing, that this move will lead to a >>>win too. But I was too lazy to create variations here). >>> >>>regards Joachim >>> >> >>Shredder is very optistic in evaluating endgames. >> >>Here, for example, take the PV in the 25-ply analysis, which starts with >>5.Bh6-d2 Kg6-g7 6.Bd2-f4 b6-b5 7.g2-g3 b5-b4 8.Kg1-g2. >> >>The PV continues with 8. .. a5, but instead black can just play 8. .. bxa3 9. >>bxa3 Na5. Now let's play vs Shredder for a few moves: 10. Be6 Bxa3 11. Bxc8 Rxc8 >>12. Ra1 Bb4 13. Bd2 Bxd2 14. Nxd2 Rc2 15. Nf3 Nc4 16. Rxa7+ Kf8 17. Nh4 Ne3+ 18. >>Kf3 Nd1 19. Kf4 Rxf2+ 20. Nf3 Nc3 21. Rxh7 Ne4 22. h4 Nd2 (finally scores go >>under +2.0) 23. Ke3 Rxf3+ 24. Kxd2 Rxg3 and black is drawing. > >another thing to keep in mind is that shredder's PV is unreliable. you can't this is a very good remark. Also note that the +1.9 for qh3 is basically because of the bad black king and white having more space. If you close your eyes, what position do you prefer to play Rxe6 or Qh3? I cannot understand that there is so many beginners here who prefer to play the very complex qh3 because 1 program which prunes even itself and its mainline says +1.9. After Rxe6 it is very clear. White is dead won and the only question is whether you win it eyes closed or whether you can also win it when asleep. That a computer doesn't score Rxe6 like +4.0 nor +5.0 is because white is down the exchange and a piece in shredder is already like 4.5 pawns or so, not to mention a rook. So pawns simply do not compensate for being an exchange down. So the 2.5 score shredder shows for Rxe6 you should see as +10.0 or so from human viewpoint. White can do nothing wrong and still will win. If i take some 1800 rated kids from my chessclub i'm sure that after Rxe6 gets played, that they will win from me with white. If they have white and play Qh3 i still win from them. Rxe6 leads to either mate, some big material win, or a dead won endgame. Even deep study i didn't find anything to delay a quick loss from black. However the number of moves and nullmoves you can do in the process is really a lot. 25 ply of shredder is like 3 nullmoves and 3 moves collecting material for white. What's beyond those nullmoves? I prefer to play a 25 ply searching shredder above a 15 ply searching shredder. It can only make mistakes with such dubious forward pruning or see more problems for it :) >just move down several moves of the PV and then let it search again, you have to >let it think at every move :-( > >my impression about the position after 1.Rxe6 Qxe6 2. Rde1 Qf5 3. >Qxf5 gxf5 4. Bxd5+ Kg6 is that it is not a clear win - there is definitely some >work ahead here. perhaps stronger players see this differently, but i think >black has some hope left.... > >cheers > martin > > > >>I think SMK's point in scoring endgames in this way is that it's very pleasant >>in a tournament to play a position like this, there are no risks. If you win two >>pawns in some unclear middlegame, there might be something you didn't evaluate >>or calculate. In this sort of position, only good things can happen. That's why >>Shredder gives +2, not because it's flat-out winning. >> >>Cheers, >>Vas >> >>>P.S.: >>>New game >>>2r1r3/p3b2p/1pn2pkB/3B1p2/3P4/P4N2/1P3PPP/4R1K1 w - - 0 1 >>> >>>Analysis by Shredder 8: >>> >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 27kN >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 27kN >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 27kN >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 27kN >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 27kN >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 27kN >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.Bd5-e6 Rc8-d8 8.d4-d5 Be7-d6 9.Bf4xd6 Re8xe6 >>>10.Re1xe6 >>> +- (1.58) Depth: 13/13 00:00:00 27kN >>>5.Bh6-f4 Kg6-g7 6.b2-b4 h7-h5 7.g2-g3 b6-b5 8.Bd5-e6 Rc8-d8 9.d4-d5 Nc6-e5 >>>10.Nf3xe5 f6xe5 11.Re1xe5 Be7-d6 12.Re5xf5 Bd6xf4 13.Rf5xf4 >>> +- (1.62) Depth: 14/24 00:00:02 738kN >>>5.Bh6-f4 Kg6-g7 6.b2-b4 b6-b5 7.Re1-c1 Nc6-b8 8.Rc1xc8 Re8xc8 9.Nf3-h4 Kg7-f8 >>>10.Bd5-b7 Rc8-c3 11.Nh4xf5 Nb8-c6 12.a3-a4 Nc6xb4 13.a4xb5 >>> ± (1.38) Depth: 15/26 00:00:07 2369kN >>>5.Bh6-f4 Nc6xd4 6.Nf3xd4 Be7xa3 7.Re1xe8 Rc8xe8 8.Nd4-f3 Ba3xb2 9.Nf3-h4+ Kg6-g7 >>>10.Kg1-f1 a7-a5 11.Nh4xf5+ Kg7-f8 12.Nf5-d6 Kf8-e7 >>> ± (1.33) Depth: 16/30 00:00:23 7471kN >>>5.Bh6-f4 Nc6xd4 6.Nf3xd4 Be7xa3 7.Re1xe8 Rc8xe8 8.g2-g4 Ba3xb2 9.g4xf5+ Kg6-g7 >>>10.Nd4-e6+ Kg7-h8 11.Kg1-f1 Re8-c8 12.Kf1-e2 Rc8-c2+ 13.Ke2-e3 a7-a5 >>> ± (1.31) Depth: 17/32 00:00:43 15168kN >>>5.Bh6-d2 Kg6-g7 6.Bd2-f4 h7-h5 7.b2-b4 b6-b5 8.Bd5-e6 Rc8-d8 9.d4-d5 Nc6-b8 >>> ± (1.32) Depth: 17/43 00:00:53 19035kN >>>5.Bh6-d2 Kg6-g7 6.Bd2-f4 b6-b5 7.Bd5-e6 Rc8-d8 8.d4-d5 Nc6-e5 9.Nf3-d4 Ne5-d3 >>>10.Be6xf5 Nd3xe1 11.Nd4-e6+ Kg7-f7 12.Ne6-g5+ f6xg5 13.h2-h4 g5xf4 >>> ± (1.32) Depth: 17/43 00:01:03 22267kN >>>5.Bh6-d2 Kg6-g7 6.b2-b4 b6-b5 7.Bd5-e6 Rc8-d8 8.d4-d5 Nc6-e5 9.Nf3-d4 Ne5-c4 >>>10.Bd2-c1 Nc4-e5 11.Nd4xb5 Ne5-d3 12.Re1-f1 Nd3xc1 >>> +- (1.43) Depth: 18/36 00:02:07 44465kN >>>5.Bh6-d2 Kg6-g7 6.b2-b4 h7-h5 7.Bd2-f4 b6-b5 8.Re1-c1 Nc6-b8 9.Rc1xc8 Re8xc8 >>>10.Nf3-h4 Kg7-f8 11.Nh4xf5 Be7xb4 12.a3xb4 >>> +- (1.63) Depth: 19/36 00:03:26 71268kN >>>5.Bh6-d2 Kg6-g7 6.b2-b4 h7-h5 7.Re1-c1 Nc6-b8 8.Rc1xc8 Re8xc8 9.Nf3-h4 Be7-f8 >>>10.Nh4xf5+ Kg7-g6 11.Bd5-e4 Rc8-d8 12.Bd2-f4 Kg6-f7 13.d4-d5 Rd8-e8 14.f2-f3 >>>a7-a5 15.b4xa5 >>> +- (1.69) Depth: 20/38 00:06:04 127926kN >>>5.Bh6-d2 Kg6-g7 6.b2-b4 a7-a5 7.Re1-e6 Nc6-d8 8.Re6xb6 a5xb4 9.a3xb4 Rc8-c2 >>>10.h2-h4 Rc2-b2 11.g2-g3 Nd8-f7 12.Bd5-c6 Re8-c8 13.Kg1-h2 >>> +- (1.69) Depth: 21/40 00:10:18 218263kN >>>5.Bh6-d2 Kg6-g7 6.b2-b4 a7-a5 7.Re1-e6 Nc6-d8 8.Re6xb6 a5xb4 9.a3xb4 Rc8-c2 >>>10.h2-h4 Rc2-b2 11.g2-g3 h7-h5 12.b4-b5 Be7-b4 13.Bd2-e3 Nd8-c6 >>> +- (1.84) Depth: 22/41 00:17:10 366131kN, tb=1 >>>5.Bh6-d2 Kg6-g7 6.b2-b4 a7-a5 7.Re1-e6 Nc6-d8 8.Re6xb6 a5xb4 9.a3xb4 Rc8-c2 >>>10.h2-h4 Rc2-b2 11.g2-g3 h7-h5 12.b4-b5 Be7-b4 13.Bd2-e3 f5-f4 14.Be3xf4 >>> +- (1.79) Depth: 23/44 00:29:23 635510kN, tb=1 >>>5.Bh6-d2 Kg6-g7 6.b2-b4 a7-a5 7.Re1-e6 Nc6-d8 8.Re6xb6 a5xb4 9.a3xb4 Rc8-c2 >>>10.g2-g3 Nd8-f7 11.Kg1-g2 Nf7-d6 12.Bd5-c6 Re8-c8 13.b4-b5 >>> +- (1.76) Depth: 24/46 00:55:18 1220985kN, tb=1 >>>5.Bh6-d2 Kg6-g7 6.Bd2-f4 b6-b5 7.g2-g3 a7-a6 8.Kg1-g2 Nc6-a5 9.Bd5-e6 Rc8-c6 >>>10.Be6-d7 Re8-d8 11.Re1xe7+ Kg7-f8 12.Bd7xc6 Kf8xe7 13.d4-d5 >>> +- (2.01) Depth: 25/44 02:02:56 2697532kN, tb=4 >>>5.Bh6-d2 Kg6-g7 6.Bd2-f4 b6-b5 7.g2-g3 b5-b4 8.Kg1-g2 a7-a5 9.Bd5xc6 Rc8xc6 >>>10.d4-d5 Rc6-c8 11.d5-d6 b4xa3 12.d6-d7 Be7-f8 13.Re1xe8 >>> +- (2.36) Depth: 25/47 02:26:20 3183940kN, tb=4
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