[3] In 1972, after being imprisoned and tortured almost to death by the Communist regime in Czechoslovakia,[4][failed verification] he was allowed to emigrate to West Germany.

He lived the remainder of his life there, and resumed his chess career with considerable success, including playing in the Interzonal in 1976 and winning the West German Championship in 1978.

World Champion Alexander Alekhine dominated the event, with Paul Keres taking second place.

Alekhine paid him a compliment in an article in the Frankfurter Zeitung and from the fifth round on, invited him every evening to analyze games and opening variations.

[3][failed verification] During this time he attempted suicide: On Christmas Eve 1969, doctors called his wife and told her that he probably would not survive the night.

In the 1950s, he became the world's leading opening expert with the publication of his four-volume opus, Theory of Modern Chess.