Yale's Jack Langer, who was the center of the controversy last year between Yale and the National Collegiate Athletic Association, has decided to quit the Bulldogs' basketball team. Langer said his decision was founded on a "lack of motivation."

Langer was barred from NCAA competition last winter because he had competed in the 1969 Maccabiah Games, an unsanctioned event. Yale supported Langer in the dispute and incurred a two-year probation from the NCAA by starting Langer on its basketball squad.

For 48 varsity games, Langer averaged 4.1 points and 3.8 rebounds per game. During last year's controversial season, the 6-8, 220 lb, center was beaten out of his starting job, and Langer also faced stiff competition for a starting position this winter.