This was a recent game between two 2500+ USCF rated players.
1.e4 c5 These starting moves define the Sicilian defense.
2.Nf3 Nc6 The other equally standard and popular options are 2…d6 or 2…e6. Both of those options would focus on opening diagonals for the Bishops.
3.Bb5 This line is commonly known as the Rossolimo variation, which intends to avoid the sharper main lines that would start with 3.d4.
3…g6 It is time to develop the Kingside pieces. Black chooses to develop the dark squared Bishop by fianchetto it to g7. Other moves such as 3…e6 or 3…d6 are also often played. It is just a matter of personal preference.
4.Bxc6 White with this exchange drastically changes the characteristic of the position. By giving up the “pair of Bishops,” White forces Black to double up two Pawns on the c file.
4…dxc6 5.d3 Bg7 6.h3 White prevents the future developing of Black’s Bishop to g4.
6…Nf6 7.Nc3 0–0 Black has already developed most of his minor pieces as well as castling. While Black has an inferior Pawn structure (at least on the surface), as compensation he has the pair of Bishops and good control of the central squares.
8.Be3 White gains a tempo by attacking the Pawn on c5 while developing at the same time.
8…b6 9.Qd2 e5 All of these moves so far have been played in dozens of master games.
10.Bh6 White could not win a Pawn by capturing with 10.Nxe5, as after the “petite combination” 10…Nxe4 and Black would win the Pawn right back.
10…Qd6 It is time to protect the Pawn on e5 as after the exchange of the dark squared Bishops, the combination mentioned in the previous commentary would no longer work.
11.0–0 In numerous past games, White chose to castle to the other side of the board instead (11.0–0–0).
11…Re8 12.Bxg7 Kxg7 Now that the opening stage of the game is over, both sides have about equal chances. The next phase of the game (the middlegame) will be extremely important. It is crucial to choose the right plan and to be alert to various tactical opportunities.
13.b3 This is to prevent a future c5-c4 push.
13…Nh5 This is the beginning of the right attacking plan. Black prepares a potential f7-f5 pawn advance as well as the jump to the active f4 square.
14.Ne2 White is trying to prepare for the upcoming Nh5-f4 jump.
14…f6 This harmless looking move actually has an aggressive idea. The idea is to prepare g6-g5-g4 and the opening of the g file.
15.g4 Generally speaking, it is not a good idea to open up the position (by moving your own pawns) in front of your castled King, while most of the pieces are still on the board, especially Queens. And this case is no exception.
15…Nf4 16.Nxf4 exf4 17.Rfe1 h5! Let the attack begin!
18.gxh5 Black’s position would also be very pleasant after 18.Nh2 when after the Pawn exchange on g4, Black would have good play along the h file.
18…Bxh3 A much more important pawn to capture than the one on h5! White is already in trouble.
19.hxg6 Kxg6 It seems that both Kings are in vulnerable positions on the open g (or h) files. However, in reality only White’s King is in realistic danger in this case. Black’s King can escape quickly on f7 when needed.
20.e5 This is just a desperate attempt to create complications.
20…fxe5 21.Qc3 Kf5! A rather unusual site, a Black King on f5, while the Queens are still on the board! Usually this would be the clear sign of trouble for Black. This is an exception from the rule! Black is winning!
22.Nh4+ Kg4 And the King marches on.
23.Ng2 Qh6 23…Qd4 is also good.
24.Rxe5 This speeds up the end. The best chance for counter play was 24.f3+.
24…Bxg2 25.Kxg2 Qh3+ 26.Kg1 Rg8 This quiet move puts White in front of unsolvable problems. Therefore, White resigned. The threat was to simply move the King (to f3 or h4) and create a discovered check. 0–1
Excellent game by black.
But also, not really great play by White. I don’t know why anyone would play 15.g4 unless this game was just for fun.
So, why did Robson blunder against his mentor?