What's Up With Eli Manning in the First Half?

5 games into the season and Eli has yet to have a first half that measures up to his second halves. What's the fricking deal? My current belief is that he looks so good in practice that Huffnagle (who is the Giant playcaller) gets a little too excited and orders up risky shots early, instead of establishing the run right way or easing into the game with some short, high percentage passes. I think Eli gets too excited from the pregame speeches or something, and they need to calm him down before they start ordering up the deep outs.

Got a better theory? Let me hear it.