Greg Cosell of NFL Films offers some very interesting takes off film study.
It boils down to things we've long talked about -- Hasselbeck brings experience and anticipation but Locker has a stronger arm and is better on the move in a way that can help Chris Johnson.
"Locker can make throws outside the pocket, whether off boot action or improvisation; Hasselbeck cannot. Designed movement off play-action would fit well with the outside-zone running ability of Titans running back Chris Johnson. The goal of the perimeter zone run game is to stretch the defense on the front side and cut or seal the pursuit on the back side. A quarterback capable of getting on the edge by design can force back-side defenders to hold their positions for an extra beat. That leaves fewer players in pursuit, giving Johnson more space to cut back, one of his strengths as a runner. There’s no question Locker would allow that tactic to be more effective.
"On the other hand, Hasselbeck is a much better pocket passer than Locker is currently. Hasselbeck would provide more stability and greater consistency. Most offensive coaches just want their game plans executed as intended. Hasselbeck, who is better at recognizing, adjusting and manipulating than Locker, would offer the Titans more continuity and greater certainty. Based on tape of him in college and from last season, Locker can be a bit undisciplined. Like many quarterbacks with excellent athletic ability and a history of making plays with their legs on Saturday afternoons, Locker has walked a fine line between following his playmaking instincts and leaving the pocket too early. The bottom line, though, is that in the NFL, quarterback is a pocket position. The traits that produce quality play from the pocket must be honed and sharpened if true consistency is to follow."
Has he honed that play from the pocket? That's the big question. If the gap between Locker and Hasselbeck in that department is sufficiently narrowed, that could be the pivot point for making the change in starters.
I've not been with the Titans daily, but I have seen a bunch of practices. Some days Locker looks like a much improved pocket passer. Some days he does not.
And while Hasselbeck will never be Locker on the move, he's worked to get better with boots and rollouts, perhaps closing the gap in that department.
We'll all have to stay tuned. Our next evidence to consider comes late Saturday in Seattle.