Now this advance gains strength due to the unsafe position of Black's king.

9...0-0 would be better.

10...Bxg5 11.Nd6+ +-

With an extra pawn and a strong attack, White is winning.

Softening up White's pawn chain before he prevents this idea by a2-a4.

Both 2.cxb5?! Qxb5 and 2.c5 Nf6 expose the d5-pawn.

Converting one of the enemy pawns into a weakness.

Before taking on c4, Black creates new weaknesses in the enemy camp.

Preparing a check on d3. Black is clearly better.