I was hoping for the five-way tie followed by a blitz tournament tomorrow (Friday), but if someone had to spoil it I'm glad it was Fabiano Caruana. Aside from his poor performance at Wijk aan Zee, it has been one success after another for him: a win in the London Chess Classic in December, and then after Wijk he enjoyed victory in the Candidates and Grenke, had a very strong second place in the U.S. Championship and then won Norway Chess.
It's also an impressive result, considering his poor start in the tournament: a bad loss to Magnus Carlsen in round 1, followed by a missed opportunity in round 2. After that he settled down, and with wins in the last two rounds wound up in clear first with 5/8. He was half a point ahead of Carlsen, Hikaru Nakamura, and Viswanathan Anand. His last round win was over Wesley So, and had the game finished in a draw both players would have joined Carlsen, Nakamura, and Anand in shared first with 4.5 points apiece.
The game could have finished in a draw, too - for that matter, So even enjoyed a significant advantage at one point. But most of the time it was Caruana who was pressing, and from that standpoint the most deserved, or maybe the least undeserved, result was a Caruana win. The critical moments came just before and after the time control. With 39...Rd2 Black would have maintained equality, but after 39...Kd8 Caruana would have been winning with most normal moves. Instead, he chose 40.h3?, and after 40...Rxh3+!, the last move of the time control (and played with little time on the clock), So found the shot that should have given him a draw. Unfortunately, after 41.gxh3 So didn't use any time to stop to double-check his opportunities after the time control. Had he done so, he would easily have found that 41...Rd2 would lead to a draw. Instead, he used all of four seconds to play 41...Rd3??, and he resigned a few moves later.
What about Carlsen? He was apparently satisfied making a quick draw with Black against Maxime Vachier-Lagrave, while Levon Aronian and Nakamura played a longer game that was never in much danger of seeing anyone lose. Anand, by contrast, played sharply with Black against Sergey Karjakin, and when Karjakin made a tactical mistake with 26.h4?(?) Anand seized his opportunity and won quickly. It would have put Anand into the playoff, had it not been for So's last lapse.
Big congratulations to Caruana, who has closed to within 20 points of Carlsen on the live list, and who showed that he can win tournaments against the very best players in the world, even when he's not in his best form.
The last four games of the event are here, with my notes to the two decisive games. Here are the final standings: