International Master 1978, Grandmaster 1997. Got acquainted with chess in Leningrad's Pioneers Palace. He was self-taught, having studied without a coach. He was Leningrad champion in 1970, 1975, 1976, and jointly in 1978.
During his playing career he defeated Viktor Korchnoi four times and beat many famous grandmasters. His best tournament achievements include first place at Polanica-Zdroj 1978 (ahead of Ulf Andersson ), and second at Trnava 1979 (after Plachetka). Tseitlin was a many-time Beer-Sheva chess club champion.
Tseitlin won the European Seniors Championship four times: in 2004 in Arvier, 2005 in Bad Homerg, 2008 in Dresden and 2013 in Plovdiv.
In 2004 Tseitlin won the first World Senior Team Championship, held in the Isle of Man, playing for team Israel together with Jacob Jacob Murey, Yair Kraidman and Yedael Stepak.
There were many international grandmasters and masters among Tseitlin's apprentices. Among his pupils were such famous chess players as grandmasters Alexander Finkel, Boris Avrukh, Ilia Smirin, Victor Mikhalevski and Dimitri Tyomkin. Mark Tseitlin assisted the rise of former world championn Anatoly Karpov, and strong Soviet grandmaster Rafael Vaganian.
He was known for his sharp tactical vision at the chessboard, and was an acknowledged expert in many chess openings, such as the Gruenfeld Defence.
Wikipedia article: Mark Tseitlin