Sinquefield Cup, Round 4: Vachier-Lagrave Wins From a Lost Position Against Carlsen, Leads the Tournament

Today was certainly an eventful day at the 2017 Sinquefield Cup, one which will gnaw at Magnus Carlsen if he doesn't come back to win the tournament. Through 40 moves of his game with Maxime Vachier-Lagrave the evaluation had been steadily equal, despite the complex position. As he has done to so many people over the years, he managed to outfox MVL, and just a few moves later he was winning. The winning move was a natural and obvious one - 46.Rd2 - and it would be surprising if Carlsen didn't see and consider it. The basic point is that if Black moves the attacked rook away, to b8, say, to neutralize any Nxb6 tricks, White plays Ka3 (so that ...Nb4 or ...Nc1 won't come with check) followed by Ne3, picking up the wayward knight on d3.

I'm not sure what Carlsen would have missed in that line; perhaps he just thought that 46.Rg2 was winning and played it. Both players made the next moves quickly: 46...Bh3 47.Rxg3 Bxf1 and now 48.Rf3, which was another error. (48.Bxd8 was equal.) Maybe Carlsen had only expected 48...Bg2 in reply, and here 49.Rxd3 Rxd3 50.Ne5+ followed by 51.Nxd3 is winning. After Vachier-Lagrave's 48...Be2, however, Carlsen was in trouble, and now he thought for more than 13 minutes. The move he chose wasn't best, though it may have been the best practical decision. Either way, MVL figured everything out perfectly, and when the dust settled after a long forcing sequence Black was up a pawn in a knight vs. bishop ending, soon to be two pawns up. Carlsen was able to set his opponent one last problem with 62.b4, but Vachier-Lagrave's great move 62...c4! sealed the victory.

That was a fine achievement by Vachier-Lagrave, after getting into trouble, and he's now the sole leader with three points out of four. Carlsen had been tied for first, so he's now a point behind, while the other co-leader coming into the round, Fabiano Caruana, is half a point back after his draw with Sergey Karjakin on the white side of a 4.d3 Anti-Berlin.

That was a quick draw, as was Levon Aronian's game with Viswanathan Anand. It was an English, and both players continued their "trends" from earlier in the event. As in his round 1 game with Ian Nepomniachtchi - where he was also White in an English - Aronian played a speedy h4-h5, while Anand continued his much more consistent, seemingly lifelong habit of swapping bishops for knights. The game was short but interesting, and in the end Anand repeated moves in a slightly better position.

The third draw of the day was also short, and lively. Peter Svidler played the Italian Game against Wesley So, but rather than go for the trendy lines with 0-0, d3, and a4, he played a good old-fashioned line with c3 and d4, meeting ...exd4 with e5. Baadur Jobava has been an advocate of this system for some time, most recently beating Vladimir Kramnik with it in Leuven. So was ready for it, and once he was on his own he did a nice job of figuring things out, and the game finished peacefully.

The last game was actually the first one to finish, and it did not have a peaceful conclusion. Hikaru Nakamura came out of the opening against Ian Nepomniachtchi in good shape, but his 20th and 21st moves were mistaken (and probably a matched pair, as Nakamura played the second move quickly). It seems that he just blundered material (rather than sacrificing it). It's hard to believe that he missed 22.Ba6, but maybe he initially thought it wasn't a big deal due to 22...Ra8 23.Rxc6 Rxa6, or maybe he saw that and missed 24.Bd6, or that after that 24...Qb7 25.Bxf8 Qxc6 26.b5 leaves Black without any last tricks to keep material equality. Whatever the story, Nakamura wound up lost after 22...Nxb4 23.Bxc8 Rxc8 24.Rxc8+ Bxc8 25.Rc1, despite having a pawn for the exchange. Nepomniachtchi did a competent job of bringing home the full point, and is now doing alright in the tournament after his 0-2 start.

Here are the pairings for round 5:

Vachier-Lagrave (3) - Aronian (2)
Anand (2) - Caruana (2.5)
So (2) - Carlsen (2)
Karjakin (2) - Nepomniachtchi (1.5)
Nakamura (1.5) - Svidler (1.5)