“One thing’s for sure: if you went to my shop and pulled the Head off the rack, the Babolat off the rack and the Wilson off the rack, and then got a hold of those three guys’ actual rackets, they won’t feel like the three that just came off the rack,” said Brad Gilbert, a coach and ESPN television commentator. “Those guys — their grips are molded to their hand, and the racket is weighted and balanced, and it’s customized.”

Federer said he had lobbied to close the gap between the store model and the racket he uses in competition. “I wanted Wilson to actually make it as close as possible,” he said in an interview.

But he and Djokovic, like many leading players, still hire a racket-servicing outfit called Priority One, which adjusts their frames and handles their stringing needs. Nadal, generally considered the least particular of the three, often relies on the tournament staff to string his rackets and on Babolat’s technicians to prepare them.

But even with models that are not customized, the differences between the frames are clear. Last week, a small group of play testers of varying skill levels used rackets provided by the manufacturers that were strung relatively close to the players’ general specifications. Among the conclusions arrived at by consensus:

¶ Nadal’s racket seemed the easiest to generate topspin with from the baseline, but was more challenging to master on touch shots closer to the net.

¶ Djokovic’s racket felt quickest through the air, particularly on the serve.

¶ Federer’s racket seemed the least forgiving on off-center hits but provided exceptional feel when contact was made with the sweet spot.

In the industry, Federer’s racket is generally considered the most challenging to handle, above all for the recreational set.