Refreshing your memory: Our study of Ehlvest-Nedev started from this position.
Ehlvest played the fantastic breakthrough 20.e5!. I asked you to try to find the forced win against 20…dxe5 (not played in the game), bringing up the following position.
21.Rxf7! is a fantastic shot. Black can decline to capture the invader, but he would be left with a severely damaged position. The main question, as is usually the case with a sacrifice, is: What if he accepts it? 21…Kxf7
I strongly suspect Ehlvest had seen 22.Qh7!, cutting off the Black king’s escape and taking aim at the bishop on g7.
White threatens Rf1+, either immediately or after Bh5+ forces Kf8. Black has no good defense. For example 22…Rg8 23.Bxe5 Qf8 (otherwise White will win the Bg7) 24.Rf1+ winning the queen.
22…Qf6 is another important defensive try. 23.Rf1 Qxf1+ 24.Bxf1 brings up the following position.
From the ‘point count’ perspective, Black is doing fine, with two rooks for the queen. But his position is completely lost, owing to positional factors: Black’s endangered monarch, White’s far more active pieces, even White’s better pawn structure. For example 24…Re7 25.Bd3 Kf8 avoids immediate disaster, but after 26.Qe4
White can either aim the dark squared bishop at the a3-f8 diagonal, or get his pawn majority in motion with c4-c5. The engine gives him +3 here! In Grandmaster chess, many ideas remain hidden in the notes, like this one.
Going back to the position after the original e4-e5 pawn break:
Black could also consider capturing with the bishop. 20…Bxe5 21.Bxe5 Rxe5
White to play and win! Hopefully you’re starting to see some of the underlying ideas in this position.