Free played for the San Diego Clippers, Philadelphia 76ers, Golden State Warriors, Cleveland Cavaliers and Houston Rockets in the National Basketball Association.

In the decisive game seven of the 1977 Eastern Conference semifinal series between the Sixers and the Boston Celtics, Free helped lead his team to victory with a game-high 27 points.

On August 28, 1980, San Diego traded Free to Golden State for Phil Smith and a first-round pick.

[6] During that year, now on the Cavaliers, Free made the playoffs for the first time since he was on the 76ers, and averaged career-playoff-highs of 26.3 points and 7.8 assists per game, during a 3-1 first round loss to the Celtics.

[8] Free later played in the United States Basketball League (USBL) for the Miami Tropics after being waived by the Philadelphia 76ers in March 1987.

He was named the USBL Playoffs MVP after leading the Tropics to the title after scoring 30 points in the championship winning game against the Rhode Island Gulls.

For Free, the highlight of that season was November 12, 1987, when he scored 38 points against the Sacramento Kings at ARCO Arena and brought the Rockets back to win the game.

When he was younger, on the playgrounds of New York City, his jump shot was a flat line drive, but he was tired of having the ball blocked, so he developed a new style of shooting.

[12] According to Free, "the fellas back in Brownsville gave me the nickname 'World' when I was in junior high... they just started calling me 'all-world', because all-city and all-county and things like that weren't good enough.