The Week in Chess

Fabiano Caruana took almost decisive control of the Sinquefield Cup after defeating Levon Aronian in a Ruy Lopez to move to a 4/4 start. Caruana introduced another new idea that he'd prepared for someone else with 15.Na2. Play was very complicated and it seemed Aronian might be close to equalisation but according to Caruana once 22.Qh5 arrived black's position was close to collapse and Caruana kept the counter-play to a minimum in scoring his fourth victory in a row. Now the question is will Caruana continue to win rather than will be win the tournament. He has a two point win and his play has been extremely convincing so far and it looks like if he continues like this he only has the power to add to his score.

Magnus Carlsen started the tournament with two quite nice draws with black but didn't play very well in round 3 and in round 4 he almost over-pressed in an endgame and lost against Veselin Topalov. 45.Rc5 would have forced the win of a piece and although there was still some play Topalov would have at the very least have enjoyed serious winning chances. Carlsen said he "didn't play at a decent level."

Hikarua Nakamura had his second black in a row and repeated the same variation of the Ruy Lopez he empoyed in round 3. Maxime Vachier-Lagrave took a small edge into the middle-game but Nakamura liquidated to a drawn position in the first game to finish.

The official live coverage reported a peak of over 31,000 viewers.

Round 4 standings: Caruana 4pts, Vachier-Lagrave 2pts, Nakamura, Aronian, Carlsen, Topalov 1.5pts.

Round 5 Sunday 31st August 2pm St Louis time: Nakamura-Caruana, Aronian-Carlsen, Topalov- Vachier-Lagrave