White prepares Be1-g3 in order to improve the bishop and reinforce the kingside defence.

Increasing the pressure towards the enemy queenside.

White has seized the initiative.

With the mission of clearing the long diagonal for the bishop.

Of course. Any other move permits 2 Bd4 virtually burying the bishop on b7.

5.Bxh2 Qxd4
5.Kxh2 Bxb4!

With a sound extra pawn, Black is winning.

Sacrificing a pawn to seize the a3-f8 diagonal with the bishop.

1.Ra1? Ba4!

Black has managed to cover the f7-pawn, but White finds a way to step up the pressure.