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View Full Version : Difficult endgame study in my game!?

Jesper Norgaard
30-12-2008, 07:07 PM
I played a game that I have analyzed with Fritz 8, and Fritz always play the position to a draw, clueless of how to progress, while after very extensive analysis I have come up with a winning plan - or so I think. But I am not quite sure. Perhaps someone with the latest Rybka can figure out whether it is a win?

Black to move and win!? :

8/8/5p2/6p1/B3Pp1p/5PnP/6P1/4k1K1 b - - 0 1

The first part is pretty straight forward. White played the mistake 1.Bb5-a4 (Ba6 must be a draw) and I played 1...Nh5? and latter pushed the f5 pawn to no avail, it was a draw. The right method is 1...Ne2+ 2.Kh2,Kf2 and the white King is further stuffed into the corner. If 3.Bb5??,Nc3 White can't stop Nd1-e3xg2 so it's all over - but Black's knight can't reach e3 or e1 without White cooperating. Thus 3.Bb3 is right - how can Black make progress?

Capablanca-Fan
30-12-2008, 07:09 PM
8/8/5p2/6p1/B3Pp1p/5PnP/6P1/4k1K1 b - - 0 1

Kevin Bonham
30-12-2008, 08:45 PM
Here are a couple of example lines I played about with using Fritz 11. In the 2...Nc3 line black won a pawn but I do not think it is enough. In the 2...Kf2 with 3.Bb3 Nd4 black was able to maneuver for what looks like a winning breakthrough with ...g4, ...Ng5 and ...h3 winning the f-pawn and creating a passed pawn. As with any very long lines generated using computers there are bound to be other ideas that should be looked at.

The question is can white stop this ...g4/...Ng5/...h3 plan. Not sure yet.

With such positions even a super-strong computer is unlikely to be able to just look at the position and give a clear verdict, unless perhaps you leave it on overnight.

1...Ne2+ 2.Kh2 Kf2 [2...Nc3 3.Bb3 Kf1 4.Bc4+ Kf2 5.Bb3 Ne2 6.Bc4 Nd4 7.Bd3 Nc6 8.Kh1 Nb4 9.Bb1 (9.Bc4?? Nc2 10.Kh2 Ne3 winning) 9...Ke1 10.Kh2 Kd2 11.e5 giving up a pawn to save the bishop but I am doubtful that black will win.] 3.Bb3 Nd4 4.Ba4 Ne6 5.Bb5 Nc5 6.Kh1 g4 7.hxg4 Ne6 8.Kh2 Ng5 9.Ba6 h3 10.gxh3 Nxf3+ 11.Kh1 Kg3 12.Bc8 Nh4 13.Kg1 f3 14.Kf1 Ng6 15.Bd7 which looks won for black

Jesper Norgaard
31-12-2008, 05:23 AM
Here are a couple of example lines I played about with using Fritz 11. In the 2...Nc3 line black won a pawn but I do not think it is enough. In the 2...Kf2 with 3.Bb3 Nd4 black was able to maneuver for what looks like a winning breakthrough with ...g4, ...Ng5 and ...h3 winning the f-pawn and creating a passed pawn. As with any very long lines generated using computers there are bound to be other ideas that should be looked at.

The question is can white stop this ...g4/...Ng5/...h3 plan. Not sure yet.

Thank you Kevin, you found at least two crucial lines and the ...g4/...Ng5/...h3 plan is definitely part of my winning plan - if it wins!
Here is what I have worked out:

1...Ne2+ 2.Kh2 Kf2 3.Bb3 Nd4 4.Ba4 Ne6! 5.Bb3! to stop an immediate g4 5...Nc5 6.Bc2 Na6! 7.Bd3 Nb4 8.Bb1 Ke1 9.Kg1! the most stubborn move 9...Ke2! 10.Kh1 Kf1! incredibly White wins the opposition in a N vs. B ending [10...Kd2!? 11.Kg1!! (11.e5? fxe5 12.Kg1 Ke1! 13.Be4 Na2 14.Bd5 Nc3 15.Bc4 Ne2+! 16.Kh2 Kf2 17.Bb5 Ng3 18.Bd3 Nf1+ and to stop Black from winning the g2 pawn it is forced to exchange, but also losing 19.Bxf1 Kxf1 20.Kh1 Kf2 21.Kh2 Ke3 22.Kg1 e4 23.fxe4 Kxe4 24.Kf2 f3!! 25.gxf3+ Kf4 26.Kg2 Ke3 winning easily) 11...Kc1? White should head back to the main line with Ke1 12.e5 fxe5 or else it Queens 13.Be4 Kd2 14.Kf2 Nd3+ 15.Bxd3! Kxd3 16.Ke1 Ke3 17.Kf1 e4 18.fxe4 Kxe4 19.Ke2! and it is a draw] 11.Kh2 Kf2 12.Kh1 Nc6 13.Bd3 only move to stop Ne5-c4 or Ne5-d3 13...Ne5 14.Bb5 g4 15.fxg4 [15.hxg4 h3! is the other important line as per the variation you showed, here it is essential that the King is on h1, if it were on h2 then Kxh3 would be possible 16.gxh3 Nxf3 another crucial position] 15...f3 16.gxf3 Nxf3 17.Ba6 Kg3 18.Bf1 Ng5 19.Bg2 Kf2 20.Kh2 Ke3 21.Kg1 Nxe4 Black constantly works with the theme of the lost pawn ending 22.Kf1 Ng3+ 23.Kg1 Ne2+ 24.Kf1! [24.Kh2? Nf4 25.Bb7 Kf2 -+ or similar positions is what Fritz 8 always walks into, it is dead lost since the pawn ending loses 26.Bc6 Ne2 27.Bb7 Ng1 28.Bc6 Nf3+ 29.Kh1 into the corner again! 29...Kg3 30.Bb7 Ng5 followed by Ng5xh3-f2xg4 and the win is trivial] 24...Nf4 25.Bb7 Nxh3 26.Kg2 Nf4+ 27.Kh2 and I haven't been able to find a convincing plan for Black, grabbing the h3 pawn is perhaps wrong because it makes the h4 pawn vulnerable, but what else?

Jesper Norgaard
01-01-2009, 10:26 AM
I think I made a mistake in my earlier analysis, going into a drawn position:

17...Ng5! I figured that this is where I failed in the earlier analysis, since [17...Kg3? 18.Bf1] makes life easier for White, and just a little pondering of Fritz 8 makes it clear that it prefers 17...Ng5 with a margin of about +0.6 extra. The position is a remarkable of bad Bishop against Knight because the position is drawn if White is to move and he could throw away his two pawns on e4 and h3 (see below) but now he must be lost: 18.Bd3 [18.Kh2 Nxe4 19.Bb7 Ng5 20.Ba8 Nf3+ is also a trivial win] 18...Kg3! [We have already seen the draw danger with the erroneous 18...Nxh3? 19.Kh2! =] 19.Bf1 Nxe4 followed by Nf2(+) and Nxh3+ Nf2 Nxg4

Here is the same position with the pawns e4 and h3 removed which is a draw:

18.Kh2! Kf3 19.Bc8 and Black can't make any progress
So that means I should return my attention to the position with the black pawn on f4 instead of h4 (white pawns on e4,g4,h3), which did not seem completely clear from Kevin's analysis. If that position also loses then I can conclude that the "study" really was correct, although simply emerged from the OTB game Jorge Martín del Campo - Jesper Nørgaard Club Mercenarios Mexico 17.th. August 1995 (drawn in 108 moves).

Jesper Norgaard
02-05-2010, 06:01 PM
I have since acquired Rybka and have gotten to the following conclusions:

15...Nf7! It's better not to exchange f4 for g2 yet, as this will keep the white king confined in the corner. The problem in earlier analysis was [15...f3 16.gxf3 Nxf3 17.Bd3! instead of the faulty {17.Ba6} 17...Ng5 18.Kh2 Ke3 19.Ba6 Nxe4 20.Kg2! Nc3 21.g5 fxg5 22.Bc8 Ne2 23.Bg4 Nf4+ 24.Kf1! and it is very difficult to make progress] so instead 16.Bc4 Ng5 17.Bd3 Ke3! 18.Bb5 Nxe4 19.Kg1 Nd2! and it seems there is no good defense to black either going Ke3-e2-e1 (if Bc6) or f3,gxf3,Kxf3! in both cases with an easy win, for instance 20.Bc6 Ke2 21.Bd5 Ke1 22.Bc6 Nb1 23.Bb5 Nc3 24.Bc6 Ne2+ 25.Kh2 Kf2 26.Be4 Nd4 27.Bd5 f3 28.g5 fxg2 29.Bxg2 fxg5 30.Bb7 Nf3+ 31.Kh1 Kg3 32.Be4 Nd4 33.Kg1 Ne2+ 34.Kf1 Nf4 etc. black is winning easily

The variation with hxg4 and gxh3 for white does not hold much more promise since the black free f4-pawn becomes a menace, so I think the "study" does hold water.