Fred L. Karpin, 73, an authority on bridge and the retired bridge columnist for the Los Angeles Times-Washington Post News Service, died of cancer April 11 at the Washington Home Hospice.

Mr. Karpin, a resident of Silver Spring, was author of 16 books on various techniques and strategies of bridge as well as dozens of magazine articles. He also had assisted Charles H. Goren and Charles J. Solomon, the former president of the World Bridge Federation, in the writing of their own books on the game.

From the late 1940s until he retired for reasons of health in 1978, Mr. Karpin taught bridge classes at the old YWCA on K Street in downtown Washington. His clients ranged from high government officials to clerks and passers-by who came in from the street. By his own estimate he averaged more than 2,000 students a year during most of that period.

Mr. Karpin and several of his supporters also insisted he was a major figure in the development of the point count method of hand evaluation in bridge. Under this system, which now is used by bridge players all over the world, points are assigned on a 4-3-2-1 basis to aces, kings, queens and jacks, and the total is used in evaluating hands and determining bids.

In the late 1940s, Mr. Karpin wrote two paperback books on the point count system. Shortly thereafter Goren came out with a book on the subject and Goren's name became closely identified with the point count method in the public mind. Other bridge experts have contended that the system was actually developed by a man named Milton C. Work during the 1930s, that Mr. Karpin improved it and that Goren and others popularized it.

Born in Brooklyn, N.Y., Mr. Karpin was a graduate of Brooklyn College, where he played baseball. He served in the Army Air Forces during World War II as a noncommissioned officer assigned to financial duties.

His professional bridge career had begun in the mid-1930s, when he went to work as one of Goren's assistants, and he received an acknowledgement in Goren's first book, "Better Bridge for Better Players."

Mr. Karpin moved to the Washington area in 1947 and began teaching bridge the following year. He also began writing books under his own name as well as serving as a writer for such bridge experts as John R. Crawford, Harry Fishbein and Richard L. Frey.

Under his own name, his books dealt with topics such as psychic and deceptive bidding, how to play slam contracts and the play of the cards.

In September 1965, Mr. Karpin became Sunday bridge editor of the Los Angeles Times-Washington Post News Service, and in 1968 he became its daily bridge columnist. Before that he had written a bridge column for the Chicago Tribune-New York News syndicate.

He became a life master in 1948.

Mr. Karpin is survived by his wife, Nettie, of Silver Spring; two daughters, Carolyn Karpin and Rita Isaacs, both of Los Angeles; and one grandson.