Bergey set ASU records for best tackling average in a season, most fumble recoveries in a season, most tackles in a game, most tackles in a season, and most career tackles. In 1968, Bergey averaged 19.6 tackles per game. He played in three post-season all-star games during his ASU career; he was selected to the All-Southland Conference team three times and to the Southland Conference All-First Decade Team. Bergey's jersey number 66 was retired by ASU.
With the Eagles, Bergey, a four-time All-Pro, set the NFL record for most interceptions by a linebacker and became the highest-paid defensive player in the league with a four-year contract for $1 million. He earned Eagles MVP status three times. Bergey recorded 233 tackles in a single season with the Eagles. He was a popular player who was the foundation of the "Gang Green" defense that brought the Eagles back to the playoffs in 1978, 1979, and to the Super Bowl in 1980. He retired from professional football in 1981. He was inducted into the Eagles Roll of Honor in 1988.