1. Frank Reich
The best backup quarterback in Buffalo Bills history shouldn't be too much of a surprise as Frank Reich would be a key part in one of the greatest moments in playoff history. He would join the Bills in 1985 after being selected in the third round of the 1985 NFL Draft.
Reich would primarily be a backup to start before going 3-0 in 1989, which would be the most starts he had in a single season with the Bills. However, he would enter franchise lore in 1992 as he would start the first playoff game against the Houston Oilers.
The reason he had to start was because in the regular season finale Jim Kelly suffered a knee injury that would not allow him to play in the Wild Card Round. It seemed like the Bills season would be coming to an end after the Oilers got out to 35-3 lead early in the third quarter.
However, Reich would take over with four straight touchdown passes in the second half that gave the Bills a 38-35 lead in the fourth quarter. The game would go to overtime before Steve Christie connected on the game-winning field goal which at the time would be the largest comeback in NFL history.
The next week, Reich would have to start again and once again the Buffalo Bills would secure the win and advance in the playoffs. In total, Frank Reich would play nine seasons with the Bills but this short two-week window showed just how valuable having a great backup can be for a team and why Frank Reich is the best backup quarterback in franchise history.