2. Josh Allen
Although Josh Allen sits behind Joe Ferguson on the Bills' all-time passing yardage list, he still checks in at number two simply because of the fact that he is, by far, a better quarterback than Ferguson ever was. At the end of his career, if Allen continues the same trajectory he's currently on, he very well might end up at number one on this list, but let's not get ahead of ourselves.
The no. 7 overall pick back in the 2018 NFL Draft, Allen came into the league as a guy with a big arm but inconsistencies and question marks when it came to accuracy and taking care of the football. Once Brian Daboll got his hands on him, though, Allen took that all-important step in his development and never looked back.
Now, Allen already finds himself third all-time on the Bills' passing chart with 18,397 yards. He's thrown 138 touchdowns to just 60 interceptions and could wind up entering the number one spot in Bills franchise touchdown passes within the next 3-4 seasons, assuming good health.
Allen might not only wind up as the Bills' all-time leading passer, but don't forget the rushing aspect to his game. Funny enough, Allen ranks 11th on the Bills' all-time rushing list. That's about as impressive as it gets for a guy who has only been in the league five seasons.