Davis was an innovator in almost every way he could be, getting most of his accomplishments with the Oakland/LA Raiders. When he was the commissioner of the AFL he set the merger wheels in motion to join the NFL, although he was never happy with the terms of which the league was forced to "subdue" to the older and more powerful NFL.
He was the coach of the Oakland Raiders following his commissioner stint from 1966-69. He also covered the duties of president and general manager. When he stepped down he hired the first of his trademark young, controversial coaches in Hall of Famer John Madden, who the Raiders won a Super Bowl under in 1976.
Davis was enamored with overly athletic players, usually with world-class speed, who his coaches built an aerial assault around. His teams were also known for having very edgy attitudes and usually led the league in all penalty categories. This usually worked until the late 1990s.
Davis moved his Raiders to Los Angeles in 1982 and subsequently moved the team back to Oakland in 1995. Both of these moves were met with much opposition from the NFL and both cities.
He was never one to go with the flow and will always be remembered as an innovator.