Greg Knapp effectively wasted an entire year of Darren McFadden’s prime by forcing a square peg into a round hole with his ill-fitting zone blocking scheme. However not even Knapp is capable of ruining one of the game’s all-time greats.
While Knapp destroyed the Raiders’ greatest strength (the run game) he did help improve Oakland’s passing game (from a statistical standpoint at least). So it’s not shocking he would land such a premium job in the assistant coach circle.
Then again, how much coaching is there to do when Peyton Manning is your pupil?