Invincible is based on the story of the player who played two seasons with which WFL team?
Invincible (2006 film):  It is based on the true story of Vince Papale (Mark Wahlberg), who played for the Philadelphia Eagles from 1976 to 1978 with the help of his coach, Dick Vermeil (Greg Kinnear). Vince Papale:  He played three seasons with the Philadelphia Eagles of the National Football League following two seasons with the Philadelphia Bell of the World Football League.
Philadelphia Bell