Wednesday, 6 October 2021

Challenge 30

PLAYED on board six (of 30) for Battersea last night in a challenge match at Battersea Labour Club against Hammersmith.

Jeremy K Hodgson (1908 ECF) - Spanton (1979 ECF)
English Symmetrical
1.c4 c5 2.g3 Nc6 3.Bg2 g6 4.e3
Overwhelmingly most popular is 4.Nc3, but the text has been used by top grandmasters, including Smyslov, Nakamura, Leko, Bareev and Ivanchuk.
4...Bg7 5.Nge2 e5
Preventing, at least for the time being, d4.
6.Nbc3 Nge7 7.0-0 
Despite what I stated earlier, 7.d4!? is possible and has been tried by strong players, although it scores a miserable 31% in ChessBase's 2021 Mega database. After 7...exd4 8.exd4 Nxd4 9.0-0 the analysis engines Stockfish14 and Komodo12.1.1 reckon White has almost full compensation for a pawn, and also after 7...cxd4 8.exd4 exd4 9.Nd5. I am not sure I understand this, at least in the first line.
7...0-0 8.Rb1 d6 9.a3
How should Black proceed?
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9...a5
This is an 'automatic' move for many players but Soltis, I believe, is one GM who has advised against ...a5 in such positions (not specifically this position). His point, if I am recalling correctly, is the hole on b5 can be a bigger problem for Black than allowing b4-b5. Instead of 9...a5, Black can meet the threat of b4 with 9...b6.
Popular in Mega21 is 9...Be6, which is the engines' choice and has been played by Botvinnik. White usually replies 10.Nd5 - the standard response when the threat of a fork on d5 prevents Black playing ....Nxd5 - although here Black has the interesting response 10...b5!?, when 11.Nxe7+ Nxe7 12.Bxa8 Qxa8 13.cxb5 is unclear - White is the exchange and a pawn up but Black has the bishop-pair and play on the light squares. The engines reckon the position is exactly balanced.
10.Nb5?!
Hoping to get in d4, presumably, but occupying b5 at this point is almost certainly premature. Normal is 10.d3, which has been played by Gufeld, Keene, Carlsen, Vachier-Lagrave and many other GMs
What should Black play?
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10...Bf5
I rejected 10....d5!, which is not in Mega21, because of 11.cxd5 Nxd5 12.Bxd5? Qxd5 13.Nc7, missing 13...Qd3 when, as in an earlier note, Black has the bishop-pair and play on the light squares, but without having to give up an exchange and a pawn. Instead the engines reckon 10...d5! should be met with 11.d3, but Black is better.
11.d3
This is preferable to 11.e4, according to the engines.
11...Qd7 12.Nec3 Rad8
The only game in Mega21 to reach the position after 12.Nec3 saw Black play the odd-looking 12...Ra6?!
13.Nd5 Nxd5
How should White recapture?
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14.Bxd5?
White has a slight edge after 14...cxd5, according to the engines.
14...Ne7
What should White do with the light-square bishop?
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15.Bg2?
Somewhat surprisingly, this loses a pawn by force. Komodo12.1.1 gives 15.e4 Nxd5!? 16.exf5 gxf5 17.Bg5, when White is also a pawn down but has disrupted Black's kingside. Stockfish14 prefers 15.Be4 Bg4!? 16.Bf3!? Bxf3 17.Qxf3, albeit giving Black a slight edge after 17...d5.
15...d5 16.Nc3
Not 16.cxd5? Qxb5.
16...dxc4 17.e4 Be6 18.dxc4 Bxc4 19.Qxd7 Rxd7 20.Rd1
How should Black proceed?
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20...Rfd8?
Completely underestimating White's counterplay. Correct is 20...Rxd1+ 21.Nxd1 Nc6 with a large advantage.
21.Rxd7 Rxd7 22.Be3 b6 23.Na4
Probably not 23.b4?! Rd3, although 24.bxc5!? Rac3 25.cxb6 is tricky. After 25...Nc6 26.b7 Rb3 27.Rxb3 Bxb3 28.Bb6 Bf8 29.Bc7 Bc4 30.a4 Bc5 31.b8=Q+ Nxb8 32.Bxb8, Stockfish14 gives Black the upper hand but Komodo12.1.1 reckons Black only has a slight advantage.
23...Rd6
White has an edge, according to the engines, after 23...Nc8?! 24.Bh3 Be6 25.Bxe6 fxe6 26.b4.
24.b4
White's queenside initiative fully compensates for being a pawn down, according to the engines.
24...cxb4 25.axb4 b5 26.Bc5!?
Possibly a tad better is the engines' 26.Nb2 axb4 27.Bc5 Rd7 28.Nxc4 bxc4 29.Rxb4, when White will regain his pawn and have the bishop-pair, albeit in a position that is not particularly favourable for bishops.
26...Rd7?
This lets White save his knight with tempo. Best seems to be 26...Rc6 27.Nb2 Nc8 28.Rd1 Bf6 29.Nxc4 bxc4 30.Rc1 axb4 31.Bxb4, although the engines reckon White holds despite being a pawn down.
27.Nb6 Rc7
How should White proceed?
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28.Bxe7?
White is better after 28.Bd6, eg 28...Rb7? loses to 29.bxa5 when the threat of Nxc4 cannot be successfully met. The engines reckon best-play goes 28...Rc6 29.Nxc4 (29.Bxe7 is also strong) Nc8 30.Bxe5 bxc4 31.Bxg7 Kxg7 32.bxa5, when White is a pawn up but not necessarily winning.
28...Rxe7 29.Nxc4 bxc4 30.bxa5 Bh6?!
30...Rc7 is equal.
What should White play?
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31.Rb8+?!
This is tempting but White seems better after the engines' 31.Bf1, eg 31...Rc7 32.a6 when White threatens Rb7 and Bxc4!? The only answer is 32...c3 but then 33.Bd3, followed by activating the king, is awkward for Black although opposite-coloured bishops must give good drawing chances.
31...Kg7 32.Rc8
Again the engines reckon Bf1!? gives an edge.
32...Ra7 33.Rxc4 Rxa5
Position after 33...Rxa5
The rest of the game can be explained by me trying to force an error in JH's mild time-trouble (we were playing with a 15-second increment, but I believe JH's clock only once dipped below three minutes).
34.Rc2 Ra1+ 35.Bf1 Ra4 36.Bg2 Ra1+ 37.Bf1 Re1 38.Re2 Rd1 39.Kg2 g5!? 40.g4 Kg6 41.Rc2 Bf8 42.Bc4 Re1?!
It was probably time to secure the draw with 42...Rd7.
43.Bd5 f6?!
Best, according to the engines, is 43...Ba3!? when 44.Rc7 Rc1 45.Bxf7+ Kf6 46.Rd7 wins a pawn but the position still looks very drawish.
44.h3
44.Rc7 poses Black problems but 44...Bg7 seems to hold, although the engines reckon White has the upper hand.
44...Ba3?!
Again inviting unnecessary difficulties. Sensible is 44...Ra1.
45.Ra2
The engines reckon 45.Rc7 Rc1 46.Rd7 is better for White, but is almost certainly still within the drawing  margin.
45...Bc5 46.Rc2 Bd4 47.Ra2 Rc1 48.Re2 Kg7 49.Ra2 Rc7 50.Re2 Kf8 51.Ra2 Ke7 52.Re2 Bc5 53.Ra2 Kd7 54.Ra6 Bd6 55.Ra2 Bc5 56.Ra6 Be7
Position after 56...Be7 - for a horrific moment I thought I was lost
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57.Be6+ Ke8 58.Ra8+ Bd8
A close escape, and one that should have acted as a warning.
59.Ra2 Rb7 60.Bd5 Rc7 61.Rb2 h5? 62.Ra2?
Position if 62.gxh5 had been played
White seems to be winning in the above diagram, eg 62...Rh7 63.Bc6+ Kf7 64.Rb8 Bc7 65.Rb7 Kg8 66.Bd5+ Kh8 67.Kg3 etc. An alternative line given by the engines runs 65...Ke6 66.Be8 Kd6 67.Bg6, again with what they reckon is a winning advantage..
62...hxg4 63.hxg4 Kd7 64.Rb2 Kd6 65.Ra2 Rh7 66.Rc2 Rh4 67.Kg3 Kd7 68.Ra2 ½–½
Hammersmith won on the evening 16-14, but with a return leg to come on Monday.

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