And Black won.

Usually in such structures, Black puts his bishop on a4, and if possible supports it by ...b7-b5, cementing the queenside. This is exactly what Black would have done here if White had dawdled.

At the cost of a pawn, White activates his bishop, and it goes from being the most passive of his pieces to the most active.

White quietly increases the pressure, whilst Black cannot coordinate his pieces.

There is now a threat of Bg4-h3, followed by Qd1-g4 and Rf2xf7. He also threatens the immediate Bg4xe6, and then Qd1-g4.

Black resigned, since after 26...fxe6, there follows Qd1-g4.

White exploits the opportunity of weakening a group of squares in the enemy camp, at a minimal material cost:

Now, the threat of the white queen appearing on h6 hangs over Black, as well as the possibility of a queen and bishop battery on the long diagonal.

This attempt to ‘plug’ the holes fails, because the weaknesses are irreparable; he cannot even get his rooks onto open files.

Black is so tied down that his queen and bishop lack even a single square each on the whole board.