I have a hard time with this issue because the posters who bring it up do so in the douchiest of manners (and seem utterly ignorant of the fact that's been brought up again and again), but let me try this as a rebuttal.
What I think you tend to see when a team (or any particular player) starts out fast in a game is some combination of 1.) a good gameplan, and/or 2.) Some overwhelming attribute the team or player possesses that is hard for the opponent to prepare for.
In other words, no amount of practice or watching of film can prepare you for Michael Vick's agility. You have to see it live to get a sense for how to deal with it (if you can).
But a good game plan can often be counteracted, especially if it isn't based on some kind of personnel deficiency. In other words, if you're facing the Saints and you have no one on your team who can cover Jimmy Graham, there's not much you can do about that. But if a team is running a certain route combinations designed to attack a favored coverage, then you probably can adjust to that and stop it.
What you see, then, when teams start fast and fade in the 2nd half, is those defensive adjustments in action. The offense came out with a plan, that plan was working, and now it's not working. To put it another way, it's not about "choking." It's not about players going into a shell. Way too much is made of that aspect of football. It's about adjustments. Can you as an offense react to the adjustments of the defense.
What I think we saw on the part of Tannehill and the Aggies was an inability to do that (there were also extenuating circumstances in several of these games, such as balls tipped in the air by WRs or utter defensive collapses). In the Sun Sentinel Draft Winds piece they brought up the fact that one of the INTs Tannehill threw in the OSU game was on a play that A&M had run successfully several times previous in the game. Then OSU adjusted and the ball was intercepted. This is a direct example of what I'm talking about but often the result of these adjustments is more subtle (blitzes out of a certain look where the defense knows the hot read and covers it, for example).
In Tannehill's defense, this is an aspect of playing quarterback that only in-game experience can teach you. No amount of film or practice work can prepare you for it. Mike Sherman, on the other hand, should have been able to adjust to these things, but perhaps he didn't know what to do or didn't feel like his quarterback could execute beyond the game plan for one reason or another. It's hard to say.
My read on this whole issue is that it's something that needs to be studied, needs to be dissected. But it's important to look beyond the box score as proof of something in and of itself. That's lazy. Look at the circumstances. Look at the situation. More important that anything, look at the game.
