The bishop is transferred to the long diagonal where it will attack Black's queenside.

In the event of 1...Bxe3?! 2.fxe3 Rxc3 3.Bxb7 White would have a huge advantage.

Removing the pawn from the bishop's sight, but now the queenside is weakened.

Fighting for the a5-pawn.

White later converted his extra pawn into victory.

Sacrificing a pawn to enter with the bishop along the b1-h7 diagonal.

Or 3.Re1 Bf5 , intending 4...g5, as well as ...Qe6-g4.

Thanks to the exposed enemy king Black is clearly better.