Originally Posted by Cheetah
What you have there is mostly momentum. It's too late especially for your fh because your contact point is a little too far back right? I don't think you make contact like you do in that vid. Seems like you hit more on the side.
you need to initiate/lead the stroke more with your torso.
The torso (after legs; kinetic chain etc etc) should turn quicker. The arm loose. That will create the lag and you should feel tension in your shoulder and chest. Then that will pull your arm and then you will get the proper ssc. The ssc is a very short action. It only lasts a few dozen millisecs or whatever it is.
Do a quicker unit turn. Feel the tension in your arm/chest.
A good way to feel is it make your racquet too heavy. Then you will feel the lag and the ssc will kick in and the racquet flies through.
edit: also another way to get the feel is to make your backswing shorter. don't take it back so far. your take back is good but if you haven't mastered the ssc stuff then it's hard to do so with a long take back. in your other vids your arm goes back to far. if it's too far back it's disconnected from the body and/or the arm is already tight so when you rotate there will be nothing to lag. do a shorter takeback to see what i mean. make it short like fed's then do a quicker unit turn. if the arm is loose then it will have a lot of 'play' or room to get stretched this way. the torso will approach facing the net then the arm muscles get tight and fling around.
with your arm far back it's like trying to stretch a rubber band that's already pulled tight.