Estrin Yakov Borisovich (21.04.1923 – 02.02.1987)

Soviet International Master and Correspondence Grandmaster (1966), a lawyer, and a paratrooper.

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).

Best results: winner or shared first at Albena 1973 and in Leipzig 1976.

The author of (with Kutyanin) Gruenfeld Defence (1959), the Two Knights Defence (1970), The United States Correspondence Chess Championship (1978), Comprehensive Chess Openings (1980),Three Double King Pawn Openings (1982), Gambits  (1983).
Estrin was also the chief editor of the 1985 Small Openings Encyclopedia.