PDA

View Full Version : Politiken Cup, Denmark



MichaelBaron
27-07-2015, 11:53 PM
Justin Tan is on 3/3 so far! :clap:

Thebes
28-07-2015, 02:26 AM
Justin Tan is on 3/3 so far! :clap:

Lost to Daniel Narodistky, a 2630 from America tonight.

Jesper Norgaard
29-07-2015, 11:52 AM
In the fifth round of Politiken Cup, GM Ragger apparently induced GM Tiger Hillarp-Persson to think that the pawn endgame was lost, so he resigned in this position after the move f4. But in fact he was resigning a drawn game.

8/8/p7/1p6/1P3pk1/P7/5KP1/8 w - - 0 1

The "winning line" he saw begins with 1.Kg1 Kg3 2.Kf1 f3 3.gxf3 Kxf3 4.Ke1 Ke3 etc. but he had overlooked an important detail.

Can you see how White (GM Hillarp-Persson) could have held the draw?

Tom M
29-07-2015, 03:17 PM
In the fifth round of Politiken Cup, GM Ragger apparently induced GM Tiger Hillarp-Persson to think that the pawn endgame was lost, so he resigned in this position after the move f4. But in fact he was resigning a drawn game.

8/8/p7/1p6/1P3pk1/P7/5KP1/8 w - - 0 1

The "winning line" he saw begins with 1.Kg1 Kg3 2.Kf1 f3 3.gxf3 Kxf3 4.Ke1 Ke3 etc. but he had overlooked an important detail.

Can you see how White (GM Hillarp-Persson) could have held the draw?

This is very similar to a variation from a pawn ending in a game played by an early 20th century master (not sure who exactly, Nimzowitsch comes to mind). White has 5. a4! and holds.

Jesper Norgaard
30-07-2015, 04:52 AM
This is very similar to a variation from a pawn ending in a game played by an early 20th century master (not sure who exactly, Nimzowitsch comes to mind). White has 5. a4! and holds.

Yes that is correct. The point is that two a-pawns is as useless as one so bxa4 is not useful for Black. If not bxa4, then White gets to play axb5 and will hold a draw answering Kxb4 with Kb2 and maintaining the opposition. For other pawns than rook pawns, usually a doubled pawn will win because the spare pawn will give a decisive tempo to force the opposing king away from the promotion square, when the front pawn has been forced to the seventh rank.

It is incredible that an experienced grandmaster would have overlooked this in a standard game with time on the clock - and just resign!

MichaelBaron
30-07-2015, 11:09 AM
After Rd 6, Justin is on 4.5 points. So is legendary James Tarjian

MichaelBaron
01-08-2015, 10:48 AM
After Rd 8 Justin is on 6 points. He drew with GM Brunello in rd 8 and is playing GM Marin next

Capablanca-Fan
01-08-2015, 11:27 PM
In the fifth round of Politiken Cup, GM Ragger apparently induced GM Tiger Hillarp-Persson to think that the pawn endgame was lost, so he resigned in this position after the move f4. But in fact he was resigning a drawn game.

8/8/p7/1p6/1P3pk1/P7/5KP1/8 w - - 0 1

The "winning line" he saw begins with 1.Kg1 Kg3 2.Kf1 f3 3.gxf3 Kxf3 4.Ke1 Ke3 etc. but he had overlooked an important detail.

Can you see how White (GM Hillarp-Persson) could have held the draw?

It's possible that the players were very familiar with the Erich Cohn vs Akiba Rubinstein 1909 (http://www.chessgames.com/perl/chessgame?gid=1119725) endgame which has often suffered faulty analysis. IIRC Jonathan Speelman (http://www.chessgames.com/player/jonathan_speelman.html) corrected the analysis relatively recently. The main line according to previous analysis was:

35. fxg4 hxg4 36. Kg1 f4 37. exf4 exf4 38. Kh1 g3 was long claimed to have won, but this is foiled by a similar line to what would have drawn the game in question. Black could win by 38... f3 rather than the pawn-clearance manoeuvre, but even simpler is capturing away from the centre with 35... fxg4, which leaves the e pawns on the board so Black can capture this one with an easy win.

Jesper Norgaard
02-08-2015, 07:19 PM
It's possible that the players were very familiar with the Erich Cohn vs Akiba Rubinstein 1909 (http://www.chessgames.com/perl/chessgame?gid=1119725) endgame which has often suffered faulty analysis. IIRC Jonathan Speelman (http://www.chessgames.com/player/jonathan_speelman.html) corrected the analysis relatively recently. The main line according to previous analysis was:

35. fxg4 hxg4 36. Kg1 f4 37. exf4 exf4 38. Kh1 g3 was long claimed to have won, but this is foiled by a similar line to what would have drawn the game in question. Black could win by 38... f3 rather than the pawn-clearance manoeuvre, but even simpler is capturing away from the centre with 35... fxg4, which leaves the e pawns on the board so Black can capture this one with an easy win.
Thanks for this comment, you are right the Tiger-Ragger game is very reminiscent of the Cohn-Rubinstein game, and indeed could have gone to the same drawing line that happened in neither game. I think Rubinstein would have sensed almost instinctively that 35...fxg4 was the right move, to not allow the e-pawns to be exchanged, had Cohn put him to this test. Playing 35...hxg4 would be like treating the pawn endgame as a middle game, where capturing towards the centre gives better control over central squares, and possibly an open h-file towards h2. With rooks lacking, all these middle game considerations are bogus, and makes 35...fxg4 the right choice.