From my father when I was growing up, I heard this story about Cowens: don't know if it was actually true or just an overblown rumor:
Cowens was an interesting center in college but considered too short. Red Auerbach went to watch him play near the end of his senior season. Auerbach watched practice, talked to players including Cowens, and went to the game. Auerbach abruptly left the game in the middle of the first quarter, and everyone thought he had seen enough and had no interest in Cowens. When the draft came, he picked Cowens. When people asked why he didn't even watch him play during the visit, Auerbach said, "After I saw that guy practice, I didn't need to see the game. I knew we wanted him." So Cowens was the opposite of "Practice?! Iverson"
At a young age I do remember seeing on TV a jump ball between Jabbar and Cowens, and Cowens won the jump even though he was 6' 7"