Originally Posted by out_grinder
I thought the big difference is that even if you swing it as hard as you physically can (regardless of whether you hit the ball or not), the actual racket is only traveling about 5% of the speed of the pro's racket.
If that was the case, they would be able to hit their forehands at least 10 times faster. The energy conversion efficiency is probably substantially worse when you swing the racket that much faster, but still.
Pros can hit forehands about 180km/h, that would mean you can only hit yours at 18km/h.