the 1927 championship match brought about an increased acceptance of hypermodern openings, which began to become a staple of competitive chess during the 1930s. In addition, elite players began to explore the Slav Defense and other QGD variants. Soviet hegemony In the 1940s the Soviet Union began a long domination of chess. The Soviet school agreed with Tarrasch and emphasized mobility. A weakness that could not be attacked was not a real weakness. The Soviet school was based on the teachings of Mikhail Chigorin (1850–1908). Mikhail Botvinnik was the first truly dominant Soviet grandmaster, having been groomed for the role due to his youth and loyalty to communism. In 1937, he won the USSR Championship, but the world championship had to wait for over a decade until after WWII had ended. The current world champion, Alexander Alekhine, had died in 1946, leaving the championship vacant. Botvinnik became world champion by winning a tournament of five top players, the World Chess Championship 1948. After WWII, hypermodern openings such as the Indian Defenses became a staple of high-level chess and have remained so ever since. In addition, the period saw a meteoric rise of the Sicilian Defense, which had been written about since the 16th century, but was uncommon until the 1950s. See also Berlin Pleiades History of chess Traité des Amateurs References Bibliography Chess theory