Ridiculous Blunder

PLAYED  a Scot in this morning's ninth and final round of the Mariánské Lázně 50+ seniors.

White to play and draw in Spanton (1854) - Ian Aird (1857)

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49.Rd4??
The double-question mark is not so much for playing a losing move - the position is not simple - but because I knew how to work out whether the pawn-ending is drawn or lost, but I played the text anyway.
The only drawing move is 49.Re4+!!, and after 49...Kf5, 50.Re1!! Stockfish10 and Komodo10 reckon Black's best try is 50...Rf2 51.Kd4!! Kf4 52.Re4+! Kg3 53.Re3+! Kg4 54.Re1!! f5 55.Ke3! Rg2 56.Rf1! Rg3+ 57.Ke2! So far all of White's moves have been only-moves, and I have tried to punctuate them in line with the John Nunn endgame convention.*
From now on it gets easier for White, for example 57...f4 allows five drawing moves, all with the rook, including 58.Rh1, while 57...Rh3!?, which is probably Black's best shot, allows two, 58.Rg1+ and 58.Rf2 (all analysis courtesy of the Nalimov endgame tablebase).
The game finished:
49...Rxd4+! (still using the Nunn convention) 50.Kxd4 Kf5 (for some reason I had only considered 50...f5??) 51.Ke3 Kg4 52.Ke2 Kg3 53.Ke3 f5 0-1
My final score of +4=2-3 saw me lose 11.2 Fide elo.

*From Wikipedia:
In his 1992 book Secrets Of Rook Endings and other books in the series (Secrets Of Minor-Piece Endings and Secrets Of Pawnless Endings), John Nunn uses … symbols in a more specific way in the context of endgames where the optimal line of play can be determined with certainty:
 ! - The only move which maintains the current evaluation of the position: if the position is theoretically drawn, this is the only move which does not lose; if the position is theoretically won, this is the only move which secures the win. An "!" is used no matter how trivial the move in question; the only exception is if it is the only legal move.

 !! - A particularly difficult-to-find "!" move.

 ? - A move which negatively affects the evaluation of the position: if the position had been drawn before the move, it is now lost; if won before the move, it is now drawn or lost.

 ?? - An obviously bad "?" move.

 !? - A move which makes the opponent's task harder or one's own task easier; for example, in a theoretically lost position, a move which forces the opponent to find several "!" moves in order to win.

 ?! - A move which makes the opponent's task easier or one's own task harder; for example, in a theoretically won position, a move which requires several subsequent "!" moves in order to win (Nunn 1999).

This convention has been used in some later works, such as Fundamental Chess Endings and Secrets Of Pawn Endings by Karsten Müller and Frank Lamprecht, but it can be safely assumed the convention is not being used unless there is a specific note otherwise. The Nunn convention cannot be used to annotate full games because the exact evaluation of a position is generally impractical to compute.

When Amateurs Play Rook Endings ...

… mistakes are sure to follow.

White to make his 57th move in Spanton (1881) - Jozef Vagovsky (1780), Olomouc seniors round two

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57.Ke2?
This really deserves ?? as it feebly turns a draw into a loss, but I am using the John Nunn endgame convention, under which it only gets one question-mark, to spare both players' blushes. Correct is 57.Ra3.
57...Rh2+ 58.Ke1

Black to play and win

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58...Rb2?
Black wins by 58...Kf3, eg 59.Ra3+ e3 60.Kd1 (Black threatened 60...Rh1#) Rh1+ 61.Kc2 Kf2 62.Ra8 e2 63.Rf8+ Kg3 64.Rh8+ Kf4 etc, or 59.Ra8 Rh1+ 60.Kd2 e3+ 61.Kd3 Rd1+ 62.Kc2 e2 63.Rf8+ Kg4 64.Rg8+ Kf5 etc.
The game finished:
59.Ra3 Rh2 60.Rb3 Ra2 61.Rc3 Rg2 62.Ra3 ½–½

Black To Play And Win

AM one of just over 350 entries in the U2000 tournament at the Gran Hotel Bali in Benidorm on Spain's Costa Blanca.
In round one I reached a position in which Black has only one winning move.
There is nothing particularly surprising in that but, in postmorteming the game with two friends I was surprised neither could find the winning move despite trying just about every legal move in the position!

Black to make his 49th move in Jose Molto Salido (1662) - Spanton (1940)

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Black is a pawn up, but the h7 pawn is very vulnerable to White's king.
A move such as 49...Ke5 is easily parried by 50.Rd7, while 49...f5 50.gxf5 gxf5 is not much help as now all Black's pawns are vulnerable.
The solution is:
49...h5
I do not give this an exclamation mark, although it would get one under the John Nunn endgame convention, as I think the move is, or at least should be, fairly easy to find (assuming you already know the idea).
50.gxh5
50.Kf4, as suggested by one friend, is no improvement after 50...Rh3, eg 51.Kg5 Rg3 etc.
50...Re5+ 51.Kg4 Rxh5 (0-1, 56 moves)

Double Rounder

TODAY was a double-round day in the Czech Tour's Highlands Open at the Hotel Atom, Trebic.
My two games could hardly have been more different - game one being effectively decided in the opening, game two deep in the ending.

Spanton (1923) - Jan Kalveus (1854), Round 7
English Opening v Dutch Defence
1.c4 f5 2.Nc3 Nf6 3.g3 c6!?
Not a popular choice, but it has been played by a 2418.
4.Bg2 d6!?
Aiming for a Stonewall with 4...d5 looks more natural.
5.d4
By transposition we have reached a position that occurs 127 times in ChessBase's 2018 Mega database.

Black's fifth move is surprising but has a certain logic

5...Be6?!
Threatening the c4 pawn, but this awkward-looking move was not played in any of the database games.
6.d5 Bf7 7.Qb3 Qd7 8.Nh3 g6 9.Be3 Bg7 10.Ng5 0-0 11.Rd1 h6?
It cannot be nice as Black having a White knight hanging around on g5, but the text spends a tempo to make White play a move he wanted to play anyway.
12.Nxf7 Rxf7 13.c5
White already has a winning advantage, according to my main analysis engines Stockfish9 and Komodo9.

Neither player has connected rooks, but Black is busted

13...cxd5
The engines suggest 13...Ng4 or 13...Na6, but have White winning.
14.Nxd5 Nc6 15.Nxf6+ Bxf6 16.Bd5 (1-0, 44 moves)

My second game today reached a knight-and-pawn ending after 39 moves.

White has just captured a rook on d1 in Miroslav Zacharias (1727) - Spanton (1923), Round 8

It is often said a knight-and-pawn ending is the closest you can get to a pawn-ending. This is true in the sense that it is much closer than, say, a rook-and-pawn ending is to a pawn-ending.
But really there are some major differences, not least the fact that one player may sac his knight to get rid of the opponent's last pawn.
With the help of Stockfish9 and Komodo9, and later the Nalimov six-figure endgame tablebase, I will try to use John Nunn's endgame convention to annotate these moves.
39...Ke5?
Black is much better after 39...Nf5 or 39...Ke6, but the natural-looking text turns a probable Black win into a drawn position.
40.Kd2?
Again natural-looking, but the engines give 40.Nc6+! Kd5 41.Nb4+! Kd4 (or 41...Kc5 42.Nd3+ Kd4 43.Kd2) 42.Kd2 and Black cannot make progress.
40...Kd4?
I had seen the superior 40...Kd5, which threatens to trap White's knight, but then played the king too far forward.
41.Nc6+ Kc5 42.Ne7 Kb4?!
Better seems to be 42...Nb7, but probably not winning.
43.Kc2 Kc5
Dead drawn is 43...Nf5? 44.Nxf5 gxf5 45.Kb2
44.Kc3 b4+ 45.Kd3 Nb5 46.Ke4
46.Ng8 is possibly the more sure-fire draw, eg 46...Nd4 47.Nf6 Nxb3 48.Nxh7 Kb5 49.Nf8 Nc5+ 50.Kc2 b3+ 51.Kc3 g5 52.Nh7 Ka4 53.Kb2 Nd3+ 54.Kb1
46...Nd4 47.Nd5 Nxb3 48.Nxb4?!
This may draw, but Komodo9 strongly prefers 48.Ke5. Stockfish9 reckons both moves draw.
48...Kxb4 49.Kxf4 Kc5 50.Kg5 Kd6 51.Kh6?
Almost certainly drawing was 51.Kf6, eg 51...Nd4 52.h4 Kd7 (Komodo9's best shot, but not good enough) 53.h5 gxh5 54.Kg5 Ke6 55.Kxh5 (tablebase draw)
51...Ke6 52.g4 Nd4 53.f4
MZ offered a draw in my time.
53...Kf6 54.Kxh7

Black to play and win

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54...Ne6?
I was torn between this and the correct 54...Ne2 (54...Nf3 also wins)
55.h4?
On 55.f5, I planned 55...Ng5+ 56.Kf6 Nf7+ 57.Kh7 g5, and wins. But we both missed that White draws in this line thanks to 56.Kg8!
If I had played 54...Ne2, then 55.f5 loses trivially to 55...g5
55...Nxf4 56.Kh6 Ne6 57.g5+ Nxg5! 58.h5
Or 58.gxh5 Kf5 etc.
58...Nf7+ 0-1

Notorious f+h Pawns

"ALL rook (and pawn) endings are drawn" is an aphorism often attributed variously to Tarrasch or Tartakower.
It sounds much more like the latter, but in any event there is a lot of truth in it, sometimes even when one player is two pawns up.
The ending of rook, f-pawn and h-pawn versus rook "has been notorious ever since the famous game Marshall-Rubinstein, San Sebastian 1911," according to Reuben Fine in Basic Chess Endings.
I reached such an ending last month in the second round of the Highlands Open in Trebic, part of the Czech Tour.
Here is the position after White's 51.Rxa3:

Black to play and draw in Spanton (1858) - Svante Norlander (1583)

Because this position can be analysed perfectly thanks to the Nalimov endgame tablebases, I shall use the John Nunn endgame convention to punctuate the moves.
Here is a subbed down version of the convention (a fuller explanation is available on Wikipedia):
!: The only move which maintains the current evaluation of a win or a draw. An ! is used no matter how trivial the move in question, unless it is the only legal move.
!!: A particularly difficult-to-find ! move.
?: A move which negatively affects the evaluation of the position. ie turns a win into a draw or a draw into a loss.
??: An obviously bad ? move.
51...Rd1+
Seven other moves maintain the draw, including 51...Rc1 and 51...Kd7 - evidence that the drawing margin in this ending is wide indeed.
52.Ke3 Rh1 53.Ra4 Ke5 54.h5 Kf6 55.h6 Re1+
No fewer than 10 moves maintain the draw here, but they do not include 55...Rxh6?, which becomes a lost pawn ending after 56.Ra6+ Kg7 57.Rxh6 Kxh6 58.Kf4 (or Ke4 or Kd4, or even Kd3).
56.Kf4 Re8?
Only one rook move draws, 57...Re7, and so does the natural-looking 57...Kg6 and even 57...Kf7.
57.Ra6+
57.Ra7 also wins.
57...Kf7

White to play and find the only move that keeps the position a win

58.Kf5!
That wasn't so difficult. Clearly White's king and f-pawn need to advance.
58...Re1

White again to play and find the only move that keeps the position a win

59.f4?
I needed to find 59.Ra8! The point is that Black's king has no useful move, while 59...Rh1 can be simply met by 60.h7 (60.Kg5 also wins).
59...Rh1 60.Ra7+ Kg8!
A fairly obvious choice, but a sign that the drawing margin has significantly narrowed.
61.Kg6 Rg1+! 62.Kf6 Kh8?
Black had to play 62...Rh1! He may have been worried by the line 63.h7+ Rxh7?? 64.Ra8mate. But 63...Kh8! draws.

White has two winning moves in this position -  I didn't find either

63.Rg7?
White wins with the understandable 63.f5 and the less obvious 63.Re7.
63...Ra1?
63.Rf1 and 63.Rh1 draw.
64.Rg6?
Again, 64.f5 and 64.Re7 win.
64...Ra6+ 65.Kg5 Ra1 66.Re6 Rg1+! 67.Kf6 Kh7 68.Kf7 Rf1 69.Rf6 Rg1
69...Rxf4?? is the only move that loses in this position!
70.f5 Rf1! 71.Kf8

My plan over the last few moves has been to sacrifice the h-pawn in return for reaching a winning Lucena position, but Black has three moves that foil it

71...Rg1?
Black had to keep his rook on the f file. After the text, I get to execute my plan.
72.Ra6 Rf1
Stockfish8 reckons 72...Rg8+ draws, but Nalimov (and Komodo9) show White winning after either legal king move.
73.f6! Kxh6 74.f7+ Kh7 75.Ra4 76.Rh4+ Kg6 77.Kg8 1-0

A Position That Baffles Computers

EVERYONE knows analysis engines are very strong these days, but there are still positions they find hard to evaluate correctly.
Most such positions occur when there are lots of men still on the board, but in my most recent tournament, the Devon County Congress at the Livermead House Hotel earlier this month, the following example arose after White's 60th move.

Spanton (169) - Daniel Gibbs (153), Rowena Bruce Challengers 2017

The game continued routinely: 60...Nd7 61.Kd4 Kxh6 62.Kxc4 Kg6 63.Kd5 Kf6 64.a6 Nb6+ 65.Kd4 Nc8 66.Nb5 Ke7 67.a7 Nb6 68.Nc7 Kd7 69.a8Q Nxa8 70.Nxa8 Kc6 1-0.
But the next day DG told me he actually had a draw, and this does seem to be the case - but you have to give analysis engines plenty of time to find it.
The key line runs: 60...c3 61.a6 Nxe4! 62.a7 c2 63.Kxe4 (63.a8Q c1Q+ doesn't change the outcome) c1Q 64.a8Q Qh1+ with a trivial draw.
So it seems 60...Nd7 should have a question mark (under the John Nunn endgame convention).
Analysis engines eventually realise White is not winning in the diagram position (although many continue to believe White is much better), but it certainly baffles them at first.