17.b4, to drive the active bishop away, seems better.

Now Black is clearly pressing – pair of bishops, centralized rooks, and the black queen dominatingly present on White’s weakened kingside.

The most elegant way to escape from under the pressure.

The young American continues in style, but the simpler 18…Rd6 was also sufficient.

19…f5 should have been played.

Here material is also equal again, but Black’s pieces have lost their coordination. He still managed to draw though.

A swinging queen’s rook. Suddenly the rook is participating!

Now the f6-knight is protected by the rook. The strong pressure against e4 forces White to exchange his h4-bishop.

Black is perfectly fine, defending actively.