Here's Delhomme:
Jake Delhomme NFL & AFL Football Statistics | Pro-Football-Reference.com
Split it into 2003-05, and then 2006-08. If those six years represent his prime, it's his age 33 season that looks like a complete outlier. Then he turns 34, and, well you saw football this season.
My point was that didn't sneak up on anyone, Delhomme had a horrendous game in the playoffs. Just saying.