In round five it was against the top seed; today in round eight it was against the second seed.
Sergej Shilov (FM2129) - Spanton (1881)
Chigorin
1.d4 d5 2.Nf3 Nc6 3.c4 Bg4 4.cxd5 Bxf3 5.gxf3 Qxd5 6.e3 e5 7.Nc3 Bb4 8.Bd2 Bxc3 9.bxc3 Nf6!?
This has been recommended by Chigorin-guru Morozevich, although it is the first time I have played it. More common in ChessBase's 2019 Mega database are 9....Qd6 and 9...exd4.
10.c4 Qd6 11.d5 Nb8
Nigel Short is among those who have played the more popular 11...Ne7.
12.Rb1 b6 13.Rg1!?
This may be a new move; it is the choice of the analysis engine Stockfish10, although Komodo9 narrowly gives the nod to 13.Bb4.
13...g6 14.Bb4 c5 15.dxc6!?
Opening lines for the bishops, but the engines prefer to keep the protected passed pawn with 15.Bc3.
15...Qxd1+ 16.Rxd1 Nxc6 17.Ba3 Rd8 18.Bd3
 |
| Black faces a tricky task as White's bishops and better development more than outweigh his inferior pawn-structure |
*****
*****
*****
*****
18...e4!?
I rejected the engines' 18...Nd7 because of 19.Bd5, when Stockfish10 gives 19...Na5 20.Bd5 Rc8. White then has a pleasant choice between winning a pawn with 21.Bxf7+ Kxf7 22.Rxd7+, and Stockfish10's preferred 21.Ke2!? Nxc4 22.Rc1 b5 23.Rgd1 a5 24.Bxc4 Rxc4 25.Rxc4 bxc4 26.Rd6, with plenty of play for being a pawn down (Black still has problems getting his king's rook into play, and the black queenside pawns are very weak).
19.fxe4
The engines prefer this to the alternative capture 19.Bxe4, but even better seems to be a move I did not consider, 19.Bc2! The point is that after 19...Rxd1+ 20.Kxd1, Black cannot play 20...exf3?? because of 21.Ba4 Kd7 22.Bb2. So in this line Black is more-or-less obliged to play 20...Kd8, when 21.fxe4 leaves White a pawn up. Black could instead try 19...Ne5!?, but then 20.Ba4 Nfd7 21.Rd5! is very strong for White, eg 21...Nxf3+ 22.Kd1 Nxg1? 23.Re5#. Black has alternatives in this last line, but none seems good.
19...Ne5 20.Ke2
Black is at least equal after 20.Be2? Rxd1+ followed by ...Nxe4.
20...Nxd3 21.Rxd3 Nxe4 22.Rgd1 Rxd3 23.Rxd3 f5 24.f3 Nf6
24...Nc5?! effectively forces a rook-and-pawn ending, but after 25.Bxc5 bxc5 26.Rd5 Ke7 27.Rxc5, I found it hard to believe Black has much chance of holding the ending a pawn down.
25.c5?!
I intended meeting 25.Rd6 with 25...0-0?! (not 25...Kf7?? 26.Rxf6+!), but Stockfish10 gives 26.Bb2 Ne8 27.Rd7 Rf7 28.Rd8 Re7 29.Ba3 Re6 30.Kd3, when Black is tied up. Better, therefore, seems to be the engines' 25...Nd7, although after 26.Re6+ Kd8 27.Bd6 Black is very passive.
25...Kf7
25...bxc5? loses the a pawn after 26.Bxc5.
26.c6
Not 26.cxb6? axb6 27.Rd6 as Black has 27...Ra8, and if 28.Bb2, then 28...Ne8=.
26...Rc8 27.Rd6 Ne8?!
I rejected 27...Rc7?! because of 28.Bb2? Ne8 29.Rd7+, missing that Black is close to winning after the simple 29...Ke6. However, the engines find 28.e4!, eg 28...Ne8 29.e5!
Best, therefore, seems to be pushing the a pawn to a6 or a5 to stop it being vulnerable to the white rook on White's seventh rank.
28.Rd7 Kf6?!
I thought 28...Kg8!?, which is the engines' choice, was simply not active enough, eg 29.Rxa7 Rxc6 30.Kd3, but the engines reckon White only has a slight edge after 30...Nc7.
29.Rxa7?!
Even stronger, according to the engines, is 29.Rxh7 Rxc6 30.Rxa7 Rc2+ 31.Kd3 Rxh2 (not 31...Rxa2?? 32.Be7+) 32.f4!? I guess the point is that White's pieces are much better coordinated than Black's, and anyway rook and bishop is nearly always a better combo than rook and knight.
29...Rxc6 30.Kd3
The engines prefer 30.Rxh7!? Rc2+ 31.Kd3 Rxa2, although the line is not as strong as first capturing on h7, as given in the previous note.
30...Nc7 31.Bb2+ Ke6 32.Bd4 h5?!
I looked at 32...f4! 33.exf4 but rejected it because 33...Kf5?? loses to 34.Be4. However, the engines show that the correct follow-up is 33...Nb5, when the game is equal.
33.Rb7 b5 34.h4 Kd7?
This loses by force. I did not like the look of 34...Kd6 35.f4, eg 35...Kd5 36.Be5, as Black is losing the b pawn, but the engines reckon White is only slightly better thanks to Black's activity in the line 36...Ne6 37.Rxb5+ Nc5+ 38.Ke2 Kc4.
35.Be5 Kc8 36.Rxc7+ Rxc7 37.Bxc7 Kxc7
 |
| White to play and win |
*****
*****
*****
*****
38.e4
The engines reckon this wins, but they are wrong, as we shall see.
Correct is 38.Kd4!, which Komodo9 comes to prefer over the text after a short while. Stockfish10 instantly prefers 38.Kd4!, but only by a narrow margin. After 38.Kd4!, best play proceeds 38...Kd6 39.f4 Kc6 40.Ke5 c5 41.Kf6 Kb4 42.Kxg6 Ka3 43.Kxh5 Kxa2 44.Kg6 b4 45.h5 b3 46.h6 b2 47.h7 b1=Q 48.h8=Q Qb6+ 49.Kxf5 Qxe3. White ends the race a pawn up, and can win in 58 moves, according to the Nalimov endgame tablebase.
After the text, White also emerges a pawn up, but this time the position is drawn.
38...fxe4+
Not 38...f4?? 39.e5, nor 38...Kd6?? 39.exf5 gxf5 40.Kd4.
39.Kxe4 Kd6 40.Kf4 Kc5 41.Kg5 Kb4 42.Kxg6 Ka3 43.f4 Kxa2 44.f5 b4 45.f6 b3 46.f7 b2 47.f8=Q b1=Q+
After 38.Kd4!, Black queens first, but the position is nevertheless a win for White. Here White queens first, but Black queens with check and so is in time to avoid Qa8+ etc.
48.Qf5 Qg1+ 49.Kxh5
White cannot win with a rook's pawn, although both engines believe White is winning, and I was able eventually to claim a draw by threefold repetition (½–½, 66 moves)
No comments:
Post a Comment