Hall of Fame
I think he has better technique than I do at least on the FH. But you can see in this vid what he is talking about. We were going the the 100 ball rally challenge and just trying to be consistent but you can see how much shorter his balls are landing than mine (hes in the white)
What technique changes should he make?
A few things for your friend (guy in the white):
1. Shoulder/unit turn: He needs to make a more dramatic unit turn on the FH and BH side, which will enable hit to gain more angular momentum and thus hit a more powerful and potent ground stroke (high resultant angular velocity). If you take a close look at the footage, you'll see that his chest is open as he loads up on the backswing for closed stance forehands, a big no-no. Even on open stance groundies, he needs a unit turn to initiate a powerful stroke. He needs to really turn that upper body so that his non-dominant shoulder is pointing in the direction of court he wants to hit into. He does a better job of turning the shoulder on the BH, but the FH needs SERIOUS work and repetition. See Federer's shoulder turn on the open-stance forehand below:
2. Contact point: it's all over the place. Of course, the height of the ball will dictate where you initiate a backswing and find the contact point. He needs to come up with a consistent contact point. For the forehand that should be far enough away from his body that the hitting arm is relatively straight and consistently out in front of his body (FH) and for the 2HBH next to the hip and slightly out in front (BH). Two examples of proper contact points below (for your friend's eastern FH grip [fed/safin] and 2HBH con grip [novak]):
If you watch the footage over again, you'll see your pal is constantly crammed on the FH side and this results in a short ball. He isn't giving this stroke enough room to operate essentially. The farther the contact point away from the hip, the more you can put on that ball. The BH contact point is awfully inconsistent and far too often he strikes the ball beneath the height of his hip. He cannot let that ball drop too far if he wants to hit through it with significant RHS and potency. He has to find that contact point more often next to the hip and really come through the ball (think of knocking books off of shelf with you frame), that's also due to his inability to straighten the left arm and plow through the ball on the two hander. He needs to use that left arm to catch the ball in the same spot every time. Tell him to practice lefty forehands to help him really hone in on the proper 2HBH contact point...
3. WEIGHT TRANSFER: your pal's biggest issue, he really isn't transferring that weight into the court. Some of those forehands he steps forward, but his weight is not shifting. He needs to transfer the weight from the back to the front. He needs to move into or towards the ball to generate more weight behind that ball, despite if it's an open or closed stance shot, you need to create a linear path (vertically for closed stance/horizontal for open stance) towards the ball. That enables the shot/groundie to carry the weight of your body and thus travel harder and faster.
Notice how Novak shifts all of his weight from the back foot (frame 2) to front foot (frame 4) on the 2HBH. This demonstrates the proper use of the kinetic chain and allows us to see what truly creates a potent stroke. Correct mechanics, not lead tape and new weighting techniques.
Let me know how it goes. Hope I can help. PM with questions @Shroud