In September 2014, Fabiano Caruana electrified the chess world by winning the Sinquefield Cup with an historic performance — starting the tournament with seven straight wins, including against Magnus Carlsen, the world champion. Fabiano’s ranking soared to No. 2 in the world and it seemed only a matter of time before he would play Carlsen for the title. Nothing he did afterward has measured up to that performance, however, and his results have often been relatively mediocre. In the Berlin Candidates tournament that is now underway, he may be finally living up to the promise shown at the Sinquefield Cup in 2014. At the halfway mark, after seven rounds, Caruana is the sole leader, with five points, a half point ahead of Shakhriyar Mamedyarov of Azerbaijan. (Each win is worth one point and each draw is worth a half point.) Three players – Ding Liren of China and Alexander Grischuk and Vladimir Kramnik of Russia – are a further point back, each with 3.5 points. The Candidates is being organized by World Chess, the commercial partner of the World Chess Federation (FIDE), the game’s governing body. The prize fund is 420,000 euros. The winner will receive 95,000 euros, but, more importantly, he will earn the right to play Carlsen in the Championship Match in London this November. The tournament has eight players. In addition to Caruana, Mamedyarov, Ding, Grischuk, and Kramnik, it includes another Russian, Sergey Karjakin; Wesley So, a compatriot of Caruana’s; and Levon Aronian of Armenia. The format is a double round-robin, with each player facing all the other competitors twice, once with each color. At this point, all the players have faced each other once. The venue for the tournament is Kühlhaus (or “cool house” in English), an industrial building in central Berlin that was built in the early 20th century as a cold-storage facility for fresh produce. Among the principal sponsors of the tournament are PhosAgro, a giant Russian fertilizer company; Kaspersky Lab, a global cybersecurity firm; E.G. Capital Advisors, an investment management company; S.T. Dupont, a global luxury goods maker; Prytek, a venture capital firm; and Isklar, a Norwegian mineral water company. Sunday, Ramin Hasanov, the Azeri ambassador to Germany, made the first ceremonial first move, in the game between Mamedyarov and Grischuk. That game ended in a draw after only 16 moves, as the players repeated moves in a sharp, but balanced position. The draw allowed Caruana, who had been tied with Mamedyarov after Round 6, to take the lead by beating Aronian. Caruana was Black and employed a delayed Queen’s Gambit Accepted. Aronian, who had been one of the pre-tournament favorites, but who has struggled, gambled out of the opening – sacrificing a pawn in an attempt to create threats against Caruana’s king. Aronian’s initiative was dangerous, and he managed to pry open the pawn protection around Caruana’s king, but only by exposing his own king. The position became extremely sharp, with both players missing their best moves. In the end, though, Caruana’s king proved to be safer. Aronian resigned on move 37 as he faced a significant loss of material. The loss left Aronian with 2.5 points, tied with So for last place. So, who had a rough start to the tournament, losing his first two games, seemed to righting himself, as he won in Round 6 by beating Aronian. But So took another step back on Sunday by losing to Karjakin. The loss was the result of a gross blunder on move 35, in a balanced endgame. All So had to do was play 35 … Rc7, instead he chose 35… Ke8, and after 36 Kb8, he faced the loss of either his rook or his knight. He resigned a few moves later. With the win, Karjakin has three points. The last game to finish was between Kramnik and Ding; it went 74 moves. It started out as a balanced strategic battle, but Kramnik made a dangerous decision on move 22 by taking a pawn on b5. That allowed Ding to force the win of material with 22 … Bf5. Ding was actually able to win Kramnik’s queen, but at the cost of a rook and a piece. A few moves later, an error by Ding (27 … Bd4?) allowed Kramnik to force the exchange of all of Ding’s remaining pieces except his queen. Kramnik was then able to build a fortress with his rook and knight. The game stretched on another 45 moves only because Kramnik tried to win by manufacturing a passed pawn. He managed to promote it, but at the cost of his rook and knight. In the end, neither player ever had any serious winning chances and the game ended in perpetual check. Ding has now drawn all his games. He is the only player to now have won or lost a game in the tournament. The second half of the tournament starts Monday, with Round 8 at 3 PM, local Berlin time. The tournament can be watched live at www.worldchess.com, the official site of the World Championship.