Here's a topical question:
Are 1-handers more prone to choking? It would make sense, seeing how the 1hbh is a bigger, faster, more free-flowing stroke. Any bit of tightness could have pronounced effects.
The one handed backhand is not bigger, faster and more free-flowing. The only serious study I read on the subject presented both strokes as equally complex and capable of generating roughly the same kind of pace. And it does make sense: take Gasquet, Almagro, Wawrinka, Federer... they all hit backhands above the 90's for winners (Gasquet breaks the three digits every now and then), exactly like on their forehand side and exactly like any other player who uses a different backhand.
Arrived at maturity, a player with either stroke might actually present very comparable score sheets. You might ask why would Federer have trouble with his backhand?
Well, watch his career. He is now better off that wing than he ever been, even when he piled up over 80 wins in a single season. If you recall, Federer didn't hit big returns in his early career: he was a monster at the baseline, so it made sense to be very conservative on the return of serve. Likewise, if you were the owners of his forehand and could move like him, would you resist hitting an inside-out forehand when you can afford to?
Federer took the very "bad" habit of running around all the time, of slicing when it wasn't necessary and of not attacking the return of serve as much as a normal player should. He barely ever played a match with the intent of using his top spin backhand purposefully until very recently... It's very clear that until he begun challenging his backhand, he could not handle as much off that wing -- it's one of those things which ultimately dooms every champion: you have to be pushed beyond your comfort zone to improve; if not, you regress.
Federer lived with ups and downs off that wing for years, but if you watch Wawrinka, it's a different story. One of the key things behind getting confident and solid is to commit yourself to doing it, even if it costs you the match... Wawrinka doesn't fool around too much with his court positioning and he commits himself to backhand rallies when necessary. Now, he can even handle Djokovic and have a chance to win the rally and we rarely see a bad backhand day from Wawrinka.
Federer now commits to hitting more backhand, commits to staying in a neutral rally. He always disliked hitting backhand rallies, always worked his way around it and that's a primary cause of mistakes: he kept trying to hit big shots when he didn't have the right ball to do it; he kept trying to change direction when he wasn't in good position to do it... He was a less exaggerated version of our amateur ball bashers on the backhand side: so frightened at the idea of having to keep up with an other player and so uncomfortable with that backhand, he figured out he'd just "gun it," going for broke way too often.