Botvinnik took an early lead in the 1940 USSR Championship, but faded badly in the later stages, eventually sharing fifth place. He attributed this to the unaccustomed difficulty of concentrating in a party-like atmosphere filled with noise and tobacco smoke. Botvinnik wrote to a friendly official, commenting that the champion was to be the winner of a match between Igor Bondarevsky and Andor Lilienthal, who had tied for first place, but had no achievements in international competition. The official's efforts led to a tournament for the title of "Absolute Champion of the USSR", whose official aim was to identify a Soviet challenger for Alekhine's title. The contestants were the top six finishers in the Soviet Championship – Bondarevsky, Lilienthal, Paul Keres (whose home country, Estonia, had recently been annexed by the Soviet Union), future World Champion Vasily Smyslov, Isaac Boleslavsky and Botvinnik – who were to play a quadruple round-robin. Botvinnik's preparation with his second, Viacheslav Ragozin, included training matches in noisy, smoky rooms and he slept in the playing room, without opening the window. He won the tournament, 2½ points ahead of Keres and three ahead of Smyslov; moreover, with plus scores in the "mini-matches" against all his rivals.