"Bill brings valuable experience as an assistant coach and head coach on both the college and NFL levels," Mangini said. "His expertise with the running game and with protections will be a big asset." The Raiders led the NFL in rushing in 2000 when Callahan was offensive coordinator, averaging 154.4 yards per game. In the Super Bowl year (2002), his first as head coach, the Raiders led the NFL in passing offense (279.7 ypg) for the first time in franchise history and also led the NFL in total offense (398.8 ypg). Callahan's 2006 Nebraska offense was one of just three schools in what was formerly Division I-A to be ranked in the top 25 in rushing offense, passing offense, total offense and scoring offense.
Callahan has 31 years of coaching experience, including nine years in the NFL. He previously served as the Raiders' offensive coordinator for four seasons (1998-2001) and was the offensive line coach for the Philadelphia Eagles (1995-97).
Under Callahan, the Raiders offense allowed a franchise-low 28 sacks in 2000 and then improved on the record, allowing only 27 sacks in 2001.
Callahan was a full-time collegiate assistant for 15 seasons, including stints at Wisconsin (1990-94), Southern Illinois (1989), Northern Arizona (1987-88) and Illinois (1981-86).
A 1978 graduate of Benedictine (Illinois), he was a three-year starter at quarterback, earning honorable-mention All-America honors in 1976 and 1977.