Mona May Karff (née Minna Ratner; 20 October 1908[1][2][3] – 10 January 1998) was an American chess player.
[5][6] Karff, along with Gisela Kahn Gresser and Mary Bain, dominated U.S. women's chess in the 1940s and early 1950s.
Mona May Karff won her first U.S. Women's Chess Champion title ahead of Mary Bain and Adele Rivero in 1938.
Her father, Aviv Ratner, a wealthy Jewish land-owner, 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.