Tuesday 2 May 2023

4NCL Final Weekend: Game Two (Analysis)

Chris Dixon (1802 ECF/1700 Fide) - Spanton (1944 ECF/1806 Fide)
Division Four: The Full Ponty v Wessex Some Stars A
Board Six (of six)
Réti
1.Nf3 Nc6 2.g3
Most popular is 2.d4, preventing ...e5.
2...e5 3.d3 d5 4.Bg2 Nf6 5.0-0 Be7
This is a Réti Opening - ChessBase classifies it as "A07: Réti Opening: New York and Capablanca Systems." But it could just as easily be classified as a Reversed Pirc, ie Black is playing the white side of a Pirc Defence but with a tempo less.
6.a3!?
This scores 54% in ChessBase's 2023 Mega database - better than any other move (apart from 6.h3, which won in its only outing), but is disliked by Stockfish15.1 and Komodo14.1.
6...a5 7.e3!?
This looks passive, but is the type of thing Black often plays when using Pirc-like systems against 1.e4 & 2.d4.
7...0-0 8.b3
How should Black proceed?
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8...Bg4
Three games reach the diagrammed position in Mega23. A 2465 played 8...Re8, a 2390 played 8...Bc5, and a 2246 played 8...e4!? The engines like the 2246's choice.
9.h3 Bh5
How should White proceed?
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10.g4!?
The engines like this and 10.Nc3.
10...Bg6 11.Nh4 Bg6 12.Nxg6
How should Black recapture?
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12...fxg6!?
Active play, but the engines prefer the conventional 12...hxg6.
13.Bb2
The engines like 13.g5!?
13...d4 14.e4?!
This weakens f4 and closes the centre, which is usually not in the interests of the player with the bishop-pair.
14...h5!
With the centre closed, Black can try to take advantage of White's weakened kingside, even if this also weakens Black's kingside, without fearing central counterplay.
15.f3 Nd8
Aiming for f4, but the engines prefer 15...Nh7.
16.Nd2 b5 17.a4 c6 18.Rf2
The engines much prefer 18.g5!?, followed by 19.f4, albeit reckoning Black has at least a slight edge.
18...Ne6 19.Nf1 h4 20.Bc1 Nh7 21.Bd2 Qc7 22.Qe1 b4 23.Bc1
The engines suggest sacrificing the f pawn with 23.f4!?, eg 23...exf4 24.e5 with a messy position, although they reckon Black is winning.
23...Bg5 24.Bxg5 Nhxg5 25.Nd2 Nf4
What should White play?
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26.Bf1!!
White gives up the exchange and a pawn, but the resulting position leaves White with a fortress that I do not believe can be breached. The engines are far from so sure, but despite the material loss they do not flash red, rather they alternate between yellow and green. Was Bf1 a stroke of genius by CD? No, not unless he was guilty of the most incredibly devious gamesmanship, and I do not for a moment think that was the case.
Here is what happened. After I played 25...Nf4, CD pondered a short while, picked up the bishop, said "Sorry," replaced the bishop and picked up the white king to move it to h2 (I presume). I said: "I'm sorry, but you picked up the bishop." He replied to the effect of: "Oh, all right then," replaced the king, thought for a few moments and moved the bishop to f1.
We should perhaps have called an arbiter, although when I told a qualified arbiter (not on duty at the tournament) what happened, he said White would have been forced to move the bishop.
Ironically, the obvious move 26.Kh2 probably loses, one line given by the engines running 26...Qe7 27.Nc4 Nfxh3! 28.Bxh3 Nxf3+ 29.Rxf3 Rxf3, when Black has rook and two pawns for (a bad) bishop and knight, and good attacking chances.
During the time it has taken me to type the above two paragraphs, Stockfish15.1 has come to list Bf1 as its top choice, although it later switches to equally liking 26.Kh2. Also possible is 26.Kh1!?, which does not lose a pawn as after 26...Ngxh3?! 27.Bxh3 Nxh3 White has 28.Rh2 and 29.Qxh4.
The engines reckon in each case (Bf1, Kh2 and Kh1), Black is winning, but this may well be an occasion where they do no understand the position.
In any event, it should be understood the double exclamation marks reflect my objective assessment of Bf1, not the motives behind it.
26...Ngxh3+ 27.Bxh3 Nxh3+ 28.Kg2 Nxf2 29.Qxf2 Qe7 30.Rh1 g5 31.Rh3
Black is winning, according to Komodo14.1, although Stockfish15.1 only gives Black the upper hand

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The problem for Black is he only has one pawn break, ie ...c4. The only plan I could come up with was to pressure f3 and g4, and look for an opportunity to sac.
31...Rf4 32.Nc4 Raf8 33.Qe2
Not 33.Nxa5?? Rxg4+.
33...Qc7 34.Qd1 Kf7
The king heads for a6.
35.Qe2 Ke8 36.Qd1 Kd8 37.Qe2 Kc8 38.Qd1 Kb7 39.Qe2 Ka6 40.Qd1 Qe7 41.Qe2 Qf6 42.Nd2 Qe6 43.Kh2?
There is no breakthrough, that I can see, if White continues to mark time with, for example, 43.Qd1.
Black to play and win
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43...Qxg4! 44.fxg4
This is clearly best, according to the engines.
44...Rf2+ 45.Qxf2
This is also the engines' top choice.
45...Rxf2+ 46.Kg1 Rxd2 47.Rh2!?
Too slow is 47.Rf3, eg 47...Rxc2 48.Rf5 Rb2 49.Rxe5 Rxb3 50.Rxg5 Rxd3 51.d5 b3 etc.
47...Rd1+
Komodo14.1 reckons 47...Rxh2? also wins, but Stockfish15.1 recognises White has (again) established a fortress that cannot be breached.
48.Kg2 Re1 49.Kf2 Rc1 50.Kf3 Kb6 51.Rf2 c5 52.Kg2 Re1 53.Kh2 c4!
Without this pseudo-sacrifice the game would be drawn.
54.bxc4 Ra1 55.Rf4 Rxa1 56.Rxe5 Ra2 57.Rxg5 Rxc2+ 58.Kh3 a4!? 59.Rb5+ Kc6 60.Rxb4
White has restored material equality, and even has two protected passed pawns. but is lost
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60...a3
An only-move, but obvious enough.
61.Rb1
Or 61.Kxh4 Rc3 62.Ra4 Rxd3 63.e5 (there is nothing better, according to the engines) Re3, after which White cannot stop both black passers.
The game finished:
61...g5 62.Ra1 Rc3 63.Rd1 a2 64.Ra1 Rxd3+ 65.Kh2 Ra3 66.e5 Kc5 67.e6 Kd6 68.c5+ Kxe6 69.c5+ Kxe6 0-1
Wessex won the match 4-2.

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