After the assault on f7 has been countered at the cost of the exchange the starting position of this line is reached.
Usual although 11. Nf3 can also be played. Nxb6 has also been played given as += by Nunn in1998.
11... Bc8b7 12. Ng1f3
12 h4 f4 is theory whereas the move played was not in my book. One point is to give the option of Qxe5 in answer to the discovery on the Queen after Nd4...
To prevent the other threat of Bg5 pinning Queen to King.
White takes now so as to be able to develop the bishop with tempo as well as bagging another pawn for the knight.
13... axb6 14. Bc1e3 Kd8c7
May not be as good as Nd4.
15. O-O-O Bf8g7
Developing and allowing the rook access to the game.
At first I wondered if this was a finger slip. Exchanging pieces quickly would leave white with a strong advantage in the endgame but if the real idea is to open up the black king why not just take the b6 pawn. Developing the h rook looks more circumspect.
16... bxc5 17. Qd5xc5 Rh8a8
Aiming to drive the Queen back with Ra5.
18. Qc5e3 Qe7f6
Lining up a discovery on b2, but possibly not the best. Post game analysis prefers e4 apparently.