csmath: 8. Be2
[standard Rossolimo move but new in position here. Caruana plays typical positional setup in Rossolimo with e4, c4, Nc3 and Qd2 all designed to obstruct central break d5]
[for the sake of attack black allows opening of a-file. Black has nice tactical resource Radjabov did not see:
17. Rxa5 d5! (opening rank for queen)
18. exd5 Bxh2
19. Kxh2 Qc7+
with equal game.]
[good practical decision - white dulls the attack of black before taking pawn by removing black night. In the next couple of moves white takes pawn on b6 and reinforces his defences aiming to keep the material advantage.]
[Serious error. The problem is that black rook on h4 has been cut from withdrawing and white uses that immediately.]
25. Bf2 Rxh3?!
[25. ...Rh5 is better, for example 26. Qd2 Rhf5, 26. b4 (or 26. Rd1) and white has whole pawn advantage and it is going to be very hard to stop passers. Radjabov decided to burn the bridges and seek chance in all out attack.]
[right call, this stops any attack.]
29. Bg3 Qxe2?
[29. ...Bxf3, 30. Raxf3 Qxe2, 31. Bxb8 is certainly more resilient as white will at least have to display some technique to convert the material advantage into a win.]
[Now black is hopelessly down material and Radjabov resigned.]
The speed with which Radjabov lost this game is indicative of his recent slump. He used to be very strong in tactical game but you could not see that here at all.
This game also shows excellent assessment by Caruana. He correctly estimated that he will be able to defend himself while keeping the pawn.