[1] A 6' 3" (1.90 m) guard from UCLA and Loyola Marymount University, Gaines played in 5 NBA seasons for 4 different teams.

The Jam won the ABA Championship in their first season of existence, thanks in part to having players like Dennis Rodman on their squad.

After winning the ABA Championship, Gaines would retire from playing basketball and start out as an assistant coach for the Long Beach Jam in their second year of existence.

[2] Gaines had prior experience with Westhead's offense, having played for him at Loyola Marymount University and with the Nuggets.

[3] In November 2011, Gaines was promoted to general manager of the Mercury, taking over a position vacated by Ann Meyers-Drysdale.

In January 2013, Gaines was temporarily promoted to being an assistant head coach for the Phoenix Suns alongside Dan Panaggio after both Dan Majerle and Elston Turner would resign from their roles after the announcement of Lindsey Hunter being the team's interim head coach.

[10] In January 2025 Japanese news media reported that Gaines was set to be named as the head coach of the Japan women's national basketball team.