Vidmar was also a top-class chess player, probably one of the best dozen players in the world from 1910 to 1930, all the while remaining an amateur. He was awarded the
Grandmaster title by
FIDE in 1950, when titles were introduced. His successes include high places at some of the top chess tournaments of his time, e.g. sixth at
Carlsbad 1907, third at
Prague 1908, first at Gothenburg 1909 (the 7th
Nordic Chess Championship), second at
San Sebastián 1911 with
Akiba Rubinstein behind
José Raúl Capablanca, first at
Budapest 1912, second at
Mannheim 1914, first at
Vienna and
Berlin in 1918, second at
Košice 1928, third at London 1922, shared first with
Alexander Alekhine at
Hastings 1925/26, third at
Semmering 1926, fourth at
New York 1927, fourth at London 1927, shared fifth at
Carlsbad 1929, tied for 4–7th at
Bled 1931, tied for 3–6th at
Stuttgart 1939, second behind
Max Euwe at Budapest 1940, first at
Basel 1952. Vidmar represented Yugoslavia in the
Chess Olympiads of
Prague 1931 (, 8½/16) and
Stockholm 1935 (board one, 8½/14). Vidmar became an
arbiter, earning the title of
International Arbiter from FIDE, and was chief referee for the
1948 World Chess Championship in
The Hague/Moscow. ==Major writings==