Do-It-Yourself Stats -
Estimates of Racket Tilt at Impact
Some of these videos are lower frame rates as can be seen from how far the incoming ball travels between frames before it is struck. To make sure you do not estimate racket tilt AFTER impacts, track the ball coming in. The ball moves the same distance between frames BEFORE it is struck. We want the racket tilt frame BEFORE impact and closest to the racket only.
AFTER impact the racket face may have been turned by the collision.
Examples, what to record
Rublev 4:35 Closed
Federer 5:11 Neutral (not much open or closed)
Alcarez 3:33 Open
...............
Pick players randomly or every 3rd player, etc. to get to 10 different random players, good camera angle to see tilt, and identify player and give the Youtube times shown at impact.
Forehand Drive Compilation, avoid motion blur that might matter to tilt estimate.
To single frame on Youtube use the period & comma keys. Go full screen. Single frame for estimates.
Playback speed option 0.25x is good to watch especially for the slowest motion videos.
Post your results or not. Try to determine what is true about the tilt on the racket face at impact for the best ATP players.