He was one of Boris Spassky 's mentors .
Alexander Kazimirovich Tolush ( 1 May 1910 -- 3 March 1969 ) was a Soviet chess grandmaster .
Alexander Kazimirovich Tolush was chess grandmaster of Boris Spassky 's mentors .
Alexander Kazimirovich Tolush ( 1 May 1910 -- 3 March 1969 ) was a Soviet chess grandmaster .