Nicolaas Cortlever

Nicolaas Cortlever ( born June 14, 1915 in Amsterdam, † 5 April 1995 ) was a strong Dutch chess player.

Cortlever took for the crew of the Netherlands five times in chess Olympiads (1936, 1939, 1950, 1952 and 1954). He won in 1939 in Beverwijk and 1942 in Leeuwarden. Several times he qualified for the Dutch national championship.

From the FIDE him the title of International Master in 1950 was awarded.

In the opening a variation of the Sicilian defense bears his name: 1.e4 c5 2.Nf3 d6 3.d4 Nf6 4.dxc5. He also created several endgame studies.