After a brief foray into over-the-board play, he turned to correspondence chess in the early 1960s with immediate success (joint first place in the USSR Correspondence Championship in 1962).

For over-the-board play, he was awarded the International Master title in 1975.

[1][note 1] Estrin wrote several chess books and was an authority on the Two Knights Defense.

His game with Hans Berliner in which Berliner played the Two Knights Defense and defeated Estrin is one of the most famous and important games in correspondence chess.

[2][3] During the Soviet Era, Estrin was one of the very few chess Authors/editors that were able to publish books in the West through direct contact with the Western Publishers.