Born October 25, 1948 Dave Cowens played in the NBA mainly as a Centre/Forward during their playing career, season(s): 1971-1983. David William Cowens is an American former professional basketball player and NBA head coach. At 6'9", he played the center position and occasionally played power forward. Cowens spent most of his playing career with the Boston Celtics. He was the 1971 NBA Rookie of the Year and the 1973 NBA Most Valuable Player.