WALTHAM — By the time Jason Collins had reached the third grade, he was 5 feet 3 inches. By sixth grade, he was 6 feet. By high school, Collins was an inch away from the 7-foot mark.

He and twin brother Jarron (about the same size) played alongside each other at Harvard-Westlake High School in North Hollywood, Calif., where they won two state titles (with 6-4 future actor Jason Segal in the role of Jason’s backup).