Echesspedia

Soviet Grandmaster (1984) and Correspondence Grandmaster (1966), a lawyer, a paratrooper and a chess professional. In over-the-board play his achievements were modest. He never qualified for the USSR Championship, but Estrin excelled in postal games, coming third after Horst Rittner and Vladimir Zagorovsky in the 6th World Correspondence Championship (1968-71) and winning the title in the 7th World Championship (1972-1976). He was also the winner of international tournament in Albena 1973 and in Leipzig 1976.
Estrin is the co-author (with Kutyanin) of a classic work on the Gruenfeld Defence (1959). He wrote extensively on opening theory, in practical Kurs Debyutov (Course of openings) with Panov, The Two Knights Defence (1970), The United States Correspondence Chess Championship (1978), Three Double King Pawn Openings (1982). Estrin was also the chief editor of the 1985 Small Openings Encyclopedia.