Buffalo has not come away impressed with either backup quarterback currently on their roster. Vince Young showed flashes of talent in the Bills' second preseason game, but took a step back on Saturday night against the Pittsburgh Steelers.
Tyler Thigpen has been even more disappointing for the Bills this preseason. Although he has extensive knowledge of Chan Gailey's offense, Thigpen has not shown the ability to accurately throw the ball. Last season, when Ryan Fitzpatrick suffered a cracked rib, the Bills decided to play the injured quarterback rather than give Thigpen a chance. That spoke volumes about the Bills' trust in Thigpen and need for a new backup quarterback.
Jackson has played for the Minnesota Vikings and Seattle Seahawks. He's shown signs of greatness, but his inconsistent play was maddening to both franchises. Jackson is currently third on the Seahawks depth chart behind rookie Russell Wilson and the highly paid Matt Flynn.
That said, Jackson is a great fit for the Bills. Chan Gailey likes to work with athletic quarterbacks; if anyone can get Jackson's true potential out, it's Gailey. I'm sure Chan Gailey sees many similarities between Tarvaris Jackson and Kordell "Slash" Stewart.
Jackson will strictly be a backup for the Bills, but he is a much better option than Vince Young and Tyler Thigpen.