The second half of the Zurich Chess Challenge not only saw more decisive games than the first half (not difficult, since there were no decisive games in the opening cycle), it saw more interesting and volatile ones as well. In the end, Fabiano Caruana (send him back!) was the deserved winner; not so much because he played especially sterling chess (no one in the tournament did), but because he made the most of his chances (at least in the second half of hte tournament) while everyone else threw away half-points on a regular basis.
Let's start with round 4, when the pairings saw Viswanathan Anand have the white pieces against Caruana, and Boris Gelfand have White against Vladimir Kramnik. Caruana had no problems in a Neo-Archangelsk Ruy, but Anand was okay too before essaying the slightly panicky 29.Rxe5. (29.Re2 was about equal, though visually Black's position seems somewhat threatening.) After the time control Anand was slightly worse, down the exchange for a pawn and generally active pieces, but on move 41 he blundered (his word) with 41.Bg2. (41.Be2 was better, keeping the N@d3 adequately guarded.) The problem with 41.Bg2 was 41...Nc8!, which not only swapped off White's best piece but also forced the subsequent exchange of White's remaining rook and the loss of White's a-pawn. After that the technical task was trivial (certainly for this level), so Anand gave up.
As for Gelfand-Kramnik, the former world champion produced an ingenious piece sacrifice (22...Nxf2!), and several moves later enjoyed a clear advantage. To maintain it, Kramnik had to play 28...Bxe4 29.Nxe4 Qa7, but his immediate 28...Qa7?? could have lost the game after 29.R4e3. Of course the position was very complicated, and White was surely concerned about threats along the a7-g1, h6-c1 and a5-e1 diagonals, not to mention the d-file. (Okay, I mentioned it.) Objectively though, it was winning. Black must attend to the threat of Nxc6, and in case of 29...Bxg2 White interpolates 30.Ncxb5 and only after, say, 30...Qd7 plays 31.Qxg2 with a winning advantage after something like 31...Bxb4 32.Qa2! Bxe1 33.Rxe1. In the game, Gelfand played 29.Ncxb5?, and Kramnik again obtained a better, maybe even winning position, but failed to convert it, and the game finished in a draw.
On to round 5. Kramnik built up a scary-looking kingside attack with White against Caruana, and although Black was objectively fine Caruana - in time trouble - went for short-term safety with an exchange sacrifice. It wasn't so bad, but thanks to his opponent's ongoing time trouble Kramnik was able to take over yet again, and had he played the consolidating 39.Rf3 he would have had excellent winning chances. Instead, 39.c5? got him into hot water, and he had to find some nice tactical ideas (40.c6!, 45.Re4!) just to save the game - which he did.
Gelfand-Anand also featured an interesting but unnecessary and slightly mistaken exchange sacrifice. Gelfand enjoyed an advantage with White in a Catalan, and with 20.Qe1 or 20.Nd2 would have had the world champion under serious pressure. Instead, he chose to sac the exchange with 20.Rxc4?!, and then gave away the rest of his advantage several moves later with 23.Rb7 (23.Rc4 kept a pleasant edge), mistakenly allowing the exchange of his last rook. (The same mistake Anand made against Caruana the round before, but here with two pawns for the exchange Gelfand had just enough of a margin to be alright.) Anand might have even pressed a little with 29...g5, preventing h4 which freed White's king to centralize. Missing or forsaking that opportunity, Gelfand drew without any real trouble.
On to the final round. With a win over Anand, Kramnik could still hope to tie Caruana for first. Despite having the black pieces, Kramnik obtained an initiative in a complicated 4.d3 Anti-Berlin, but an inaccurate 20th move and a howler on move 21 cost him the game and finished his tournament with a rude bump. Kramnik had decent chances to score at least 2.5 points in the final three games, but only managed a single point. Not the way to go into the Candidates in two weeks!
Likewise, Gelfand finished with a winless -1 score after losing his last round game to Caruana. Early in the middlegame he sacrificed a pawn to reach a position where his activity was probably just about enough to hold a draw, but Caruana, like Carlsen, requires his opponents to prove their ability to hold a position over many, many moves before letting them off the hook. Gelfand seemed to have decent drawing chances after the first time control, with all the pawns on one side of the board and the ideal h5-g6-f7 defensive pawn chain. His decision to push the pawns looked dangerous, but had he played the normal 50...hxg4+ it seemed he would have pretty decent chances to hold. His 50...fxg4+ looked odd - why give White an unearned passed e-pawn? - but even so the outcome was only certain after the incredible 55...h4?? It's hard to know what he even thought this achieved. Maybe he thought that after 56.gxh4 g3 57.Bg1 Bh6 he'd be able to play 58...Bxf4 59.exf4 Rxf4 and pick up the h-pawn too, reaching a drawn rook vs. rook and bishop ending? White has many ways to thwart that plan, however, including the move Caruana chose: 58.Kg2. Black resigned after that, since 58...Bxf4 59.exf4 Rxf4 60.Kxg3 keeps the h-pawn.
So Caruana finished with a convincing, undefeated +2 in the tournament, and earned his way back to #7 on the rating list. Like Carlsen, his play is rarely "shiny" or characterized by dramatic opening successes; rather, like the great Norwegian (and players like Smyslov and Karpov before them), he makes a lot of very good moves, and is remarkably resilient both in defense and in prosecuting the slightest advantage.
Anand's play wasn't fantastic, but resilience and a last-round gift made up for his own unforced error against Caruana, and his 50% score was enough for clear second.
Kramnik and Gelfand can both be somewhat disappointed with their play and their results, but getting in six games with great, tough opponents playing unfamiliar positions (due to avoiding their real opening prep) will surely help warm them up for the Candidates. And that should be a fantastic event!