Boston Celtics' Basketball 1988 with 13 Signatures and is a Clubhouse Version. It has been PSA Authenticated. Most of the signatures are full names. PSA says that a Clubhouse version means that the players authorized a coach or manager to sign the ball for them. It is a Spalding ball with the Boston Celtics logo. Some of the players are; Kevin McHale, Robert Parish, Jim Roberts, Larry Bird, Brad Lohaus, Dennis Johnson, Dick Minniefield and Fred Roberts, to name a few. The document from PSA. will be included. The ball is inflated and in excellent condition. According to PSA finding a ball that the players actually signed is very rare. Most that you see for sale on marketplaces are clubhouse.