Originally Posted by LeeD
I thought about that before the video loaded.
Swing is maybe 35 degrees upwards, as little as 30 degrees.
He's hitting a rallyball, to sustain the rally, against a deep ball, and he's going for lots of topspin to control depth and keep the opponent back.
Now, "almost 45 degrees" is realistic, but NOT the same as "up around 45 degrees".
The basic point is that there is a significant upward component to the swing to generate the topspin that is seen in the modern game. It's not subtle, and it's not generated by closing the racquet face. The players are swinging the racquet up at very steep angles and very high racquet head speeds. It's not rocket science.
Here's Fed in a match ripping one, and the angle is pretty steep. I'll let Lee determine the exact measurement.