The evolution of Roddick’s game has never surprised me because I never thought it was his natural game to hit particularly penetrating shots from the baseline à la Berdych. I always saw him as a big serving counter-puncher who had to go outside of his comfort zone to be aggressive from the baseline. The key factor is in Roddick’s forehand grip. Like Djokovic and Nadal, he uses a variation of the western grip and subsequently has more difficulty hitting through the court than those with milder grips. That’s not to say he cannot hit through the court, just that it’s less natural, requires more contortion in the wrist and effort in the wrist, arm and upper body than players with milder grips such as Federer, Del Potro and Berdych. It’s just not very efficient in relation to pace generation.
Out of Djokovic, Nadal and Roddick, Djokovic is the player who is able to flatten the ball best, but even his predominant tendency is still that of a counter-puncher and he is not able to cut through the court as comfortably as a Federer, Del-potro or Berdych, despite his obvious strength, same applies to Nadal and Roddick even more. The idea behind grip = destiny is pertinent here. The fact is that it’s more difficult to be aggressive on the forehand side with a western grip than it is with a semi-western or eastern. The benefit of the western grip is that it can help you impart more topspin and control because it takes the edge of the pace you generate due to the fact that it naturally facilitates a more vertical swing path for the racket head, which imparts more topspin, but also prevents the racket from going through the ball as much. You gain consistency, but lose pace.
That’s what is going on here. Roddick is reverting to what is comfortable, which is hard not to do. Whenever he plays a Federer, Djokovic or Nadal, he does try to be more aggressive, because he has to in order to stand a chance at all, but this is not his natural game and requires more energy than is ideal; note after beating Federer in Miami this year he said he was too tired to be competitive against Juan Monaco in the next round. Admittedly he said he was not fit, but I also think the energy he has to put into being aggressive was also a factor. For the other players he plays his natural game because it is usually enough and it is prudent to do so for the aforementioned reasons. Djokovic and Nadal are similar in this regard, but with more success.