NORMAN, Okla. (AP) — Oklahoma coach Bob Stoops abruptly announced his retirement Wednesday, a stunning offseason move by the 56-year-old future Hall of Famer who led the Sooners to 10 conference championships and a national title in 18 seasons.

Stoops was the longest-tenured active coach in major college football, taking the job at Oklahoma a day before Kirk Ferentz started at Iowa. Stoops was 190-48 (.798) at Oklahoma — his only college head-coaching job — giving him more victories than Sooners coaching greats Barry Switzer (157) and Bud Wilkinson (145).

"I understand there has been some spec...