Career
He earned the International Master title in 1976 by winning the World Junior Championship at Groningen, ahead of such noted players as Ľubomír Ftáčnik and Oleg Romanishin. His father, Carl Diesen, was a tournament chess player as early as the mid-1940s, which resulted in strong family support for Mark"s chess career. He grew up in Potomac, Maryland, a suburb of Washington, District of Columbia, which afforded him numerous opportunities to play.
lieutenant also allowed Mark to become a student of Grandmaster Lubosh Kavalek, who was one of the strongest players in the world.
While Kavalek was noted as a tactician, Diesen was a player with a positional style that made him a difficult opponent to face for even the most experienced IMs and GMs. Among the top players he defeated in his short career were Larry Evans, Borislav Ivkov, John Nunn, and Eugenio Torre.
Diesen played in the 1980 United States. Championship – his only appearance in the Closed Championship – but had to withdraw after three rounds after injuring himself in a fall. A graduate of the University of Tennessee, he had a degree in Chemical Engineering.
After dropping out of chess, he worked as a reservoir engineer for Shell Oil, Pennzoil and Noble Energy.
After his withdrawal from chess he continued to influence and inspire through IM with Mark Diesen and coaching within the Conroe-Houston area. Diesen was married with three daughters (Gina, Amy, and Sarah).
