Day 1 of round 4 of the 2013 World Cup got off to a slow start with super-quick draws in the Dmitry Andreikin - Sergey Karjakin and Hikaru Nakamura - Anton Korobov games, but then it heated up. (That's not to say the players with White had no ambitions - that surely was not the case with at least Nakamura. But neither achieved even the most minuscule of edges, and in neither case was there anything for White to do.)
The next draw was a 27-mover between Maxime Vachier-Lagrave and Boris Gelfand, but don't be fooled for an instant by the move count. This was a very complicated game that would have been an impressive achievement by both sides, were it not all or practically home prep for both of them.
Le Quang Liem drew an up and down game with Peter Svidler. Le's plan with queenside castling was a new wrinkle in the line, at least to Svidler, and soon White was much better. In fact, had Le played 23.Rxd5 Svidler professed himself just about ready to resign, and that isn't just a matter of Svidler's typical self-deprecation. He really would have been completely lost. After that reprieve he was still worse, but not lost, and by the end he may have been even better with 38...Ke6 instead of 38...Kf6, going for a repetition. After Susan Polgar and Lawrence Trent prodded him about that, Svidler bemoaned his being a "chicken". Despite all those misadventures, he's still tied in the match and has White tomorrow.
The last draw was between Alexander Morozevich and Evgeny Tomashevsky, and the latter continued his fine, solid play, gradually equalizing and then even enjoying a little pull by the end.
Now to the wins. The first game to finish, barely, was Fabiano Caruana's win over Julio Granda Zuniga. Granda was at most slightly worse before playing 20...f5??; after it, he was dead lost, and after the obvious 21.exf6 he resigned. Black can't take twice on e2 because White will trade rooks and promote the f-pawn, while 21...Qa6 can be met several ways, most appealingly and effectively by 22.f7! Rxe2 23.Bf5+! gxf5 24.Rxd8+ Kxd8 25.f8Q+ Kd7 (25...Re8 26.Rd1+ mates quickly) 26.Qf7+ when Black can move his king to the c-file and get mated with 27.Qxc7, or do something else and lose huge quantities of material after 27.Rd1+.
The second decisive game to finish was a greater achievement by the winner. Gata Kamsky won a very impressive attacking game against Shakhriyar Mamedyarov, filled with a whole series of sacrifices. Really a beautiful game.
Finally, Vladimir Kramnik won with the black pieces against Vassily Ivanchuk, though as he told Polgar and Trent - the first thing out of his mouth after the congratulations - it would have been much better had it happened in London. In a queen and rook ending Ivanchuk underestimated the danger of pushing pawns around his king, and it cost him.
So far my predictions for the round are going well: three right and none wrong! Meanwhile, enjoy all eight games here, with perfunctory comments in some cases and a bit of analysis in others.