Hey Fabian, ok I think he’s got a pretty nice stroke overall but definitely a few things that will really help him. I’ll start with the last bit of the question which it’s what’s wrong and how to correct it. In my opinion he is focusing a bit to much on the wrist and shot is a little bit flappy and out of control which makes it lose consistency. So he needs to try to generate a bit more of the shot with the forearm and then just accelerate the wrist through on contact with the ball. At the moment the wrist is moving quite a bit throughout the whole shot. It should be used to accelerate through and brush up on the contact to generate more spin and quality.
I also feel he needs to “coil up” a bit more in preparation for the shot, so by this I mean getting lower lower in his legs with more bend in the knees and then pushing up into the ball through the shot. The best way to think of this is like squashing down a spring and then letting go, the energy gets released quickly. So this is a good way to explain it to him. Some of the things he does really well are getting being each shot nicely and also having a really stable and consistent upper body with a good forward position. This is really good and if he can add in the parts I mentioned and keep these going I think he’ll have a great shot going!
Just quickly on the list of topics you put above a couple of points as well for you 🙂
1) Nice solid ready position, maybe just a touch lower in the legs
2) Backswing should drop down slightly lower and come back a little closer to the stomach
3) Forward swing as I said using the forearm more and a bit less wrist, finish position very good and compact
4) Recovery and timing is pretty good, just focus on hitting very slightly after top of the bounce but no later
5) Contact is pretty good and bat angle is fine just needs to adapt depending on the incoming spin
6) A bit more body turn will help him but this isn’t vital right now
7) His footwork is pretty good, getting behind each shot, but a bit heavy footed, try to be light on his feet
I hope this all makes sense and helps, let me know if you have any questions on this.
Cheers, Tom