The black pieces are directed at the kingside, which is defended only by White’s queen, which in her turn also defends the Ba4. If Black plays some sort of attacking move on the kingside, White will give an intermediate check with the bishop from b3, freeing his queen. Consequently, there followed instead the deflection motif:

And the destruction sacrifice...

The white king is all alone, and his other pieces are unable to come to his aid.

White resigned.

The white rooks have not yet taken up the open files, whilst his other pieces are on the queenside, far from his king. These factors gave Black the idea of landing a blow:

The light squares start to creak, and the pieces cannot come to help their king. Black’s attack assumes a decisive character.

Other replies do not help either:
A) 23.f4 Rc2 24.fxe5 Rxg2+ 25.Kh1 Qc2–+;
B) 23.gxh3 Qxh3 24.f4 (24.Be2 Rc6–+) 24...Rc2 25.Rf2 Nf3+–+;
C) 23.Be2 Rc2 24.Bd1 (24.Bh5 Qf5–+; 24.gxh3 Rxe2 25.Bd6 Nf3+ 26.Kh1 d4–+) 24...Rc6 25.f4 Bxg2 26.Rf2 Be4 27.fxe5 Qh3–+.

The concluding move of a nice combination. White resigned.

White has full control of the e-file, but Black’s pawn formation is harmonious, and there are no entry squares in his position. At the same time, the Nc4 is cut off from the kingside, and the Bg7 is restricted by both his own pawns and the white chain on c3-d4. Meanwhile, White’s own dark-squared bishop is not a very active piece. This all points to a small sacrifice, which has more of a positional rather than a tactical character.

Black loses time, which allows White to bring the inactive Ra1 into the attack. It was essential to find the problem-like 26...Rh6! 27.Nxf7 Qxf7 28.g4 Rf6 29.Qe8+ Bf8 30.Qxf7+ Kxf7, with a double-edged, roughly equal endgame.