KARFF, MONA MAY (1912–1998), seven-time winner of the U.S. women's chess championship and one of the first four Americans to be named an international woman master by the International Chess Federation (1950). Born in Bessarabia, Karff learned chess from her father, Aviv Ratner, a Zionist who later became a real estate magnate in Israel. Karff, an intensely private person who was always mysterious about her background, came to the United States in the 1930s. She was married briefly to a cousin, Abe Karff, a Boston lawyer. Between 1938, when she won her first national title at the second U.S. women's championship, to 1974, when she achieved her seventh national championship, Karff was in the forefront of women's chess in the United States. Less consistently successful in top international competitions, she placed sixth representing Palestine in the women's world championships in Stockholm in 1937 and came in fifth representing the United States at the 1939 world championships in Buenos Aires. Karff, who remained involved in the world of competitive chess throughout her life, had a long-term romantic relationship with Dr. Edward Lasker (d. 1981), a five-time winner of the U.S. Chess Open.
M. Oehlert, "Karff, M. May," in: P.E. Hyman and D.D. Moore (eds.), Jewish Women in America, vol. 1 (1997), 723; New York Times, Obituary (Jan. 18, 1998).