Monday 30 July 2018

Small Margins

HULL can lay claim to a candidate for the world's smallest window.
It is in the wall of The George, formerly a coaching inn but now a pub in a street named - I kid you not - Land Of Green Ginger, which is in the old town.
Possibly the world's smallest window
The window is so narrow you may not be able to make it out in the photo, but it is to the right of the plaque, directly above the Welcome sign.
Apparently a boy used to be posted on the inside to warn staff when a coach pulled up (why he couldn't do that sitting outside the front door is not explained).
Whatever the truth, anyone looking through the window has a very small margin for spotting what is going on outside (or inside, for that matter, if in the street).
My win today in round two of  the 50+ Seniors at the British Championships also featured a small margin.
I was much too ambitious in the early stages on the white side of a Nimzo-Indian, but by the time we reached the middlegame I had gained a pleasant edge.
Position after 15...h7-h6 in Spanton (1927) - Nigel S Towers (1834)
Here I played 16.g4 to prevent Black gaining counterplay with ...f5. Instead he played 16...f6, presumably to stop me trying to open lines with g5.
The game continued 17.Be3 Nc7 18.b4 b6, and now I began rerouting my knight: 19.Nf2 Bh7 20.Nh1
NST played 20...a5?!, which allowed me to close the queenside with 21.b5
With the centre and queenside blocked, the game will be decided on the kingside, where I still had hopes of opening lines for my bishops and heavy pieces.
After 21...g5 22.Ng3 Ne8 I should have increased the pressure with something like 23.Kf2 Kf7 24.h4.
Instead I jumped in prematurely with my knight: 23.Nf5?
There followed: 23...Bxf5 24.gxf5 Ng7 25.h4 Nh5 26.Kf2 Nf4
After pressing the clock, NST offered a draw. I probably should have accepted, but played on with 27.Bxf4? exf4 28.Rh1 No prizes for guessing who has the better minor piece.
Just seven moves later, we reached the following position, which I thought was OK for White, but, according to the analysis engine Stockfish9, is winning for Black.
Position after 35.Rh1-g1
Luckily for me, NST blundered: 35...Nf7?? 36.Qxg4
Stockfish9 reckons Black is winning after the simple 35...Kf8, or even 35...h5!? The point about the latter is that 36.Qxf4? loses to 36...Ng4+! 37.Rxg4 hxg4 38.Qxg4 Rxh4.
Even after the moves played,  the game is far from easily won as the position remains very blocked and Black has much the better minor piece.
However, as in yesterday's game, I eventually got down to a rook-and-pawn ending, only this time I was the player with the extra pawn.
Position after 69...Kd7-d6
White is winning easily, but I managed to give Black drawing chances, and at one point I thought I might be losing!
The game went 70.Re2 h5+! Black's best chance - he must create counterplay and hope to pull off a swindle.
71.Kxg5 h4 72.Rh2 h3 73.Kg4 (73.f6 is easier, but the text is still winning) 73...Ke5 74.f4+ Kd4 75.Rxh3 Rg8+ 76.Kxf3 Kxc4 77.d6 Kxb5 78.Ke4 Kc6
After pressing his clock, NST fairly quickly offered me a draw.
79.Rh6?? b5
Black should now draw, according to my analysis engines, and during the game I thought I could be losing. Instead of 79.Rh6?? I should have played 79.f6 Kxd6 80.Kf5, eg 80...Rf8 81.Rd3+ Kc6 82.Ke6 etc. Also winning was 79.Ke5 Re8+ 80.Kf6.
80.f6 Rf8+?
80...b4 is a clear-cut draw, according to the engines, but not 80...Kxd6?? f7+.
81.Ke5 Re8+?
This loses trivially. Again, ...b4 was best. When I first looked at this position after the game, Komodo9 gave 81...b4 82.Ke6? Re8+ 83.Kf7 Re4, assessing it as dead equal. But Stockfish9 gives 82.axb4 axb4 83.Ke6 Re8+ 84.Kf7 Re4 85.f3 b5 86.Rh1 Re2 87.Rg1 b2 88.Kg6! Rg2+ 89.Rxg2 b1=Q, when Black has queened first, but White wins after 90.f7.
In this latter line, if 86...Kxd6, then 87.Kg6 Rg4 88.Kh5 Rg8 89.f7 Rb8 90.f6 c4 91.Re1 b2 92.Re8 Rxe8 93.fxe8=Q b1=Q. Both sides have queened and have a pawn, but according to the Nalimov tablebases, White mates in 28 moves starting with 94.Qe7+.
There may well be mistakes in this analysis, but in any event 81...b4 was definitely the move to play.
The game finished 82.Kf5 b4 (too late now) 83.f7 Rf8 84.Ke6 b3 85.Ke7 c4 86.Kxf8 b2 87.d7+ Kc7 88.d8=Q+ 1-0

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