Pawn Sacrifice, Dark Square Control

We started our discussion of Novikov-Jacimovic from this position, with White to play:

White decided to win a pawn with 10.Bxf4? exf4 11.Qxf4, bringing up the following position.

There’s always a danger in using the engine to explain the mistakes of a stronger player. One can easily appear glib, imposing instructive remarks upon engine evaluations. Nonetheless, I’ll try. By exchanging his dark squared bishop in this pawn structure, White drastically weakened his control of the dark squares. Black’s dark squared bishop will be very strong with no opponent. Black’s previously passive rook on e8 also comes to life, attacking the pawn on e4. And in the time White will need to waste retreating his queen, Black will develop an initiative.

None of this is to say that Grandmaster Igor Novikov doesn’t understand these ideas; of course he does. According to his wikipedia profile, he was ranked inside the World’s top 100 seven times. But in the fog of war, with numerous options available and no engine evaluation to fall back on, chess is a profoundly difficult game. So much so that even extremely strong players can make relatively simple positional mistakes.

As for how Black should continue: Grandmaster Jacimovic continued in exemplary fashion. First he activated his bishop with 11…Bg5, forcing the White queen to retreat with 12.Qf3.

Then he developed his knight with 12…Nd7, with designs on both the c5 and e5 squares. Play continued 13.Qd1 Nc5

When Black’s dark square control offered more than full compensation for the pawn. Over the next series of moves, his advantage only grew. I will give them without commentary, but with a few diagrams, so you can see how he played on the dark squares.

14.Be2 Bf4 15.Qc2 Bd7