Mack was selected by the Rams with the second overall pick of the 1966 NFL draft and played at left guard for the Rams for 13 seasons from 1966 to 1978. During his NFL career, Mack played in 11 Pro Bowls and appeared in 184 consecutive games, 176 as a starter, over 13 seasons.
Mack enrolled at the University of Michigan in 1962 and was a member of the Michigan Wolverines football team from 1962 to 1965.[4] As a sophomore in 1963, he played at the end position and spent most of the season on the bench.[4][5] After the 1963 season, Mack switched to the tackle position at the suggestion of Michigan coach Bump Elliott. Mack later referred to the position change as "the big break of my life," an opportunity that "turned my whole experience in terms of football around."[5]
Mack was selected by the Los Angeles Rams in the first round, as the second overall pick, in the 1966 NFL draft.[1][11] During Mack's rookie season with the Rams, starter Don Chuy was injured during the fifth game of the season, allowing Mack to move into the lineup.[12] He started nine games during the 1966 season and became a fixture for the Rams at the left guard position for the next 13 seasons.[1] During his NFL career, Mack never missed a game due to injury, appearing in 184 consecutive contests, the third longest streak in Rams history behind Merlin Olsen and Jack Youngblood.[13]
During Mack's career with the Rams, the club enjoyed a .720 winning percentage with a won-lost-tie record of 129–48–7, won their division eight times (1967, 1969, and 1973–1978), and reached four NFC championship games. In 1973, the Rams scored led the NFL with 388 points (27.7 points/game). In 1974, the Rams lost to the Minnesota Vikings by four points in the 1974 NFC Championship Game, with a controversial penalty call against Mack costing the Rams a touchdown. The Rams had the ball at the one-yard line on second down when the Vikings' Alan Page made contact with Mack; the referee called illegal procedure on Mack, but replays showed that Mack had not moved. After the game, Mack insisted he had not moved but credited Page with "a smart play" in making contact since a penalty, if called against the Vikings, would have been meaningless.[14][15]
Mack was selected to 11 Pro Bowls, the first coming after his second season in 1967. He missed only one Pro Bowl appearance the rest of his career (1976). Mack's 11 invitations earned him a third-place tie with Bob Lilly and Ken Houston for the most selections of all time. Mack was selected first-team All-Pro four times (1969, 1971, 1973, 1974) and second-team All-Pro four times (1968, 1970, 1972, and 1975). In addition, he was named All-NFC eight times between 1970 and 1978.[1]
After retiring from football, Mack worked as an engineer, using the engineering degree he received at the University of Michigan.[5] He eventually became a lobbyist for Bechtel Group, Inc.[18]
Mack has a daughter named Carrie who attended Quince Orchard High School in Gaithersburg, MD (Class of 1992).
^Michigan Athletic Hall of Honor. Bentley Historical Library (archives of the University of Michigan and the Michigan Athletic Department) website. Retrieved September 9, 2011.