Until their simultaneous failure last round, either Fabiano Caruana or Boris Gelfand - or both - led the Baku Grand Prix, and I think that with the exception of round 3, no one else shared that lead with them. Coming into round 10 there was a six-way tie for first, and with Caruana in particular having lost two of his last three games it looked as if they had been swallowed up by the field.
Not so! Caruana and Gelfand both won in round 10, and while there were two other decisive results all of the players who entered the round tied with them finished it trailing them once more. Leinier Dominguez had White against Caruana, but played unsuccessfully in the English and soon found himself suffering in a position where Black dominated the dark squares while White suffered with a bad light-squared bishop. White was worse, but wasn't losing until he swapped rooks on move 26. He clearly wanted to open lines on the queenside for counterplay, but the end result was a vulnerable king. Caruana took speedy advantage, ensuring himself of at least a share of the lead while leaving Dominguez in the cellar.
Gelfand took on one of the co-leaders, Teimour Radjabov, and won very smoothly - too smoothly, perhaps. Radjabov eschewed his old favorite King's Indian and went into an Open Catalan, which is a Gelfand specialty. They followed a Kramnik-Radjabov game from their 2011 Candidates match, and although Radjabov produced the novelty on move 14 Gelfand was quickly better. Radjabov was clearly worse by move 19, and a further error on move 24 resulted in a 28 move win by the 2012 "vice-champion".
Sergey Karjakin and Peter Svidler entered the round tied for first, and both may have had their moments of optimism. For Karjakin, he was on the white side of a Ruy line that had scored 8.5/9; for Svidler - who of course improved on the earlier games - he obtained a dangerous kingside attack with the help of a piece sacrifice. Luckily for Karjakin, Svidler either missed something or underestimated his chances, and took a perpetual in a clearly better position.
Hikaru Nakamura was another leader who could only draw, not managing much on the white side of an Exchange Slav.
Evgeny Tomashevsky remained within half a point of the lead, making it a four-way tie behind Caruana and Gelfand, by defeating Dmitry Andreikin. The game was decided in what I assume was mutual time pressure, wherein Andreikin made more, and more severe, errors than his opponent. By the time they made the time control Tomashevsky was up three pawns for nothing, so Andreikin gave up on his 41st turn.
Finally, the game between Rustam Kasimdzhanov and Alexander Grischuk was won by the latter when the former FIDE champ underestimated Black's kingside play.
- Mamedyarov (4.5) - Kasimdzhanov (4.5)
- Radjabov (5) - Nakamura (5.5)
- Svidler (5.5) - Gelfand (6)
- Andreikin (4) - Karjakin (5.5)
- Caruana (6) - Tomashevsky (5.5)
- Grischuk (5) - Dominguez (3)