In the FYB video here: http://www.youtube.com/watch?v=2gZ6RIkQ9IU there are a few things that are stressed: 1) The wrist should remain laid back before and during contact. In other words, there should be no flexion of the wrist until well after contact, and the wrist should remain extended before and through contact. 2) Advanced players can start to introduce pronation / wrist deviation to aid in generating topspin 3) Sometimes, the pronation/deviation can give the illusion of wrist flexion when watching full speed video. Now my question is whether 1) holds true in all circumstances. I'm not arguing that one should actively flex the wrist, but aren't there circumstances where the wrist will naturally flex to a more or less neutral position right at contact? Look at this super slow motion footage of a federer forehand: http://www.youtube.com/watch?v=ji914RSFrew Unless my eyes are deceiving me, it seems clear that there is a significant component of wrist flexion that occurs right before contact. It appears that the previous link in the kinetic chain (the forearm) slows down and the momentum gets channeled through the wrist joint creating a nice whip effect. I suspect that this is more the case when one is hitting a flat forehand, with the racquet face perpendicular to ground during the forward swing (and square to target).