Alexander Konstantinovich Zaitsev (1935–1971) was a Russian chess Grandmaster (GM), and a key figure in the Soviet chess world. Zaitsev was born on the 15th of July 1935 in Omsk, Russia, and began playing chess at nine years old. He won the Junior Chess Championship of the Soviet Union in 1951 at the limit age of 16, in 1956 winning the title of Russian Federation Champion and in 1960, the title of Moscow champion. In 1965, he won the Soviet Championship.
Zaitsev was awarded the GM title in 1965, and became a promising candidate for future world chess champion due to his exceptional skills. He also held important administrative positions, being elected to the Central Committee of the Dynamo, the Soviet sports society, and becoming head of the chess section.
Zaitsev, however, couldn't realize his full potential due to health problems. He suffered from rheumatic heart disease for a long period and died during a minor surgical operation on the 31st of October 1971.
In addition to his individual achievements, Zaitsev was an active participant in team chess events. He represented the USSR in the 1964 and 1966 Chess Olympiads, contributing to the team's gold medal victories in both the events. He had also helped the USSR team to win the European Championship in 1965.
Overall, the win percentages of the games he played were: 48.4% with white pieces, 34.38% with black pieces and 54.4% from both colors.
The Zaitsev Variation, a popular variation of the Ruy Lopez Opening in chess, is named after him.