Mrs. Karff (20 October 1908 or 1911 or 20 October 1914 – 10 January 1998) was one of the top female U.S. players in the 1940's and 1950's.
She was born Mona May Ratner in Bessarabia, a province in Tsarist Russia. Sometime after the Bolshevik Revolution of 1917 her family moved to Tel-Aviv. Her father, Aviv Ratner, a Zionist who acquired a vast amount of property in Tel Aviv and later became one of the richest men in Israel, had taught her to play chess when she was 9 years old. Because of her natural ability, she started playing in tournaments in Tel-Aviv and developed into a strong player. In 1937, while in Palestine, she played on their team at the women's world championships.
In the 1930s, she moved to Boston, Massachusetts where she married her cousin, an attorney named Abraham S. Karff (15 March 1901 – 16 February 1995). The marriage was brief and she never remarried but her long-time romantic relationship with Edward Lasker was never a secret. Lasker was 25 years older than Karff but friends recalled them as a perfectly matched couple. She spoke eight languages fluently, traveled extensively and spent a great deal of her money on modern art. Nobody knows exactly where her fortune came from, but she was known to be a shrewd investor in Wall Street and supposedly made millions in the stock market. Living in New York City, she was a daily visitor at the Marshall Chess Club where one of her regular partners was Edward Lasker. She once told a friend, “I was born with chess in my blood.”
Karff played in three Women's World Chess Championships: 1937 Stockholm, playing for Palestine and placing sixth (won by Vera Menchik); 1939 Buenos Aires, playing for the U.S. and placing 5th (also won by Menchik); 1949 Moscow, playing for the U.S. (won by Lyudmila Rudenko). When FIDE established titles in 1950, she was one of four American women to receive the title of Woman International Master. On the 1956 USCF rating list, the first I could find with women's ratings, the top women were Gisela Gresser (2056), Sonja Graf (2040), Nancy Roos (2008), and Karff (2004). This is probably somewhat skewed because in those days women generally did not compete in men's events.
Karff, along with Gisela Gresser and Mary Bain, dominated U.S. women's chess in the 1940s and early 1950s. Karff won her first U.S. Women's Champion title against Adele Rivero (later Adele Belcher) in 1938 and was to win the title six more times: 1941, 1943, 1946, 1948 (sharing it with Gresser), 1953 and in 1974 (at age 66). She also won four consecutive U.S. Open women's titles. Despite her success in U.S. tournaments she never fared well in foreign competition and always finished well back in the field. In 1948 she toured Europe for the One World movement.
She died on January 10, 1998 at her home on Riverside Drive in Manhattan; the cause was heart failure. She was 86. Her only surviving relatives lived in Tel Aviv.