csmath: T-sky choses Caro-Kann? Probably to avoid Scotch.
Of course Caruana plays Advance.
[Novelty though hardly anything impressive. Tomashevsky probably expects difficult game against the opponent that needs a win.]
[While black position looks "Semi-Slav" passive this particular move is not making it any better. Black loses pawn with hardly any compensation.]
[Caruana is probably shooting for the ending with as little pieces as possible. While this is a practical decision it is not motivated by the position. 22. Qe1 looks as a better alternative and with the same idea of exchange but on more favorable terms either getting the exchange on a5 or on on a1 but with white queen controlling a-file.]
[Black is also in some hurry? 24. ...Nxc3 looks more solid as white is going to have a long way to make anything happen.]
[Strange decision. But even without the following tactics black is assisting white with his desire to simplify the game. This cannot be considered favorable on any grounds.]
[Effective tactical strike.]
[Black was probably under the impression that this will solve his problems.]
33. Qe8 Bg8
[Caruana sees further, the pawn cannot be stopped without material loss. The game is over.]
Very nice tactical strike overlooked or miscalculated by black. Simple game but effective nevertheless.