Sergej Dyachkov is a Ukranian-Russian chess Grandmaster, FIDE International Organizer, and a FIDE International Arbiter for chess. He was born on April 13, 1976, in Ukraine. He earned the title of Grandmaster in 2002, and in 2004 became an International Arbiter and an International Organizer in 2012.
As a player, Dyachkov has won multiple chess championships, including the Championship of Russia among boys under 14 in 1990, and the Championship of Moscow in 2000, among others. He also represented Russia in the 2006 Chess Olympiad. Between 2004-2006, he worked as a coach for the National Team of Russia for the Disabled.
As an organizer and arbiter, Dyachkov has managed many prestigious chess events such as the World Championship Match 2012, Women's World Chess Championship 2013, and multiple FIDE Grand Prix Tournaments. He has also served as an arbiter in a variety of world championships, Olympiads, and Grand Prix events.
In addition, Dyachkov has authored several chess books and is the creator of a popular chess software program, Peshka. Controversies involving his alleged involvement in cheating during the Dutch Open in 2014 and issues in the Moscow Open in 2015 were recorded and proven false by FIDE Ethics Commission.