Brett Williams was a 12th round draft pick out of Austin Peay by the Minnesota Vikings in the 1981 NFL colleg draft, Williams was released by the Vikings in August of 1981 and signed by the New England Patriots in March of 1982.  Williams was released by the Patriots in November, 1982, and then played 1983 with the Houston Gamblers of the USFL and in 1984 with the Oakland Invaders, also of the USFL.  Williams signed with the Montreal Concorde for August of 1985 and played two seasons (1984-85) in la bell province.  Williams had just  three sacks in 11 games in his first season ,but exploded in 1986 for 21 quarterback sacks to win both East and CFL All-Stars.  When the Alouettes foled just prior to the start of he 1987 season, Williams was selected in the first round of the dispersal draft by the Saskatchewan Roughriders, but traded before the season started to BC for their first round pick in the 1988 CFL college draft.  Williams playd one season (1987) in BC and was then traded in March of 1988 to Edmonton for offensive lineman Leo Blanchard.  Williams would play four seasons in Edmonton 91988-91), winning West division All-Star in all four seasons and CFL All-Stars in 1988 and 1991.  Williams became a free agent and signed with Hamilton for the 1992 season.  Williams remained with the Tiger-Cats in 1993, and finished his CFL career with two game in Shrevport in 1994.  In all, Williams finished with 89 quarterback sacks in his career.

Brett Williams in Wikipedia

Defensive tackle stats were first kept in 1987 and special teams tackles and tackes for losses in 1991.