Oswald (Ozzie, Jake) Jacoby (December 8, 1902 – June 27, 1984) was an American contract bridge player and author, considered one of the greatest players of all time.
Born in Brooklyn, he was taught to play whist at the age of six. During World War I, he joined the army at 15 by lying about his age, but spent most of his time there playing poker. Dropping out of Columbia University to become an actuary, he became the youngest person ever to pass the examination of the Society of Actuaries, at the age of 21.
Throughout his career, he also worked as a bridge columnist. He soon achieved fame as a player at both auction and contract bridge, but achieved international renown via success in the Culbertson Match, partnering Sidney Lenz. He was a member of the famous "Four Horsemen" and "Four Aces" teams.
He captained the North American and US teams that won the Bermuda Bowl in both 1970 and 1971. In 1983, he was awarded the prestigious Charles H. Goren Award. During a long playing career, he won tournaments with his son, James Jacoby, as well as his wife of over 50 years, Mary Zita Jacoby.
He pionereed many bidding ideas, including the Jacoby transfer and Jacoby 2NT bids.
A prolific writer, he wrote over 10,000 newspaper articles on bridge, and his many books include volumes on poker, gin rummy, canasta, and the mathematics of card games. He also released a record titled How to Win at Championship Bridge.