I had a great training session yesterday. I was hosting my in-laws and went to a wedding last week, so I hadn't played in about a week except for a session with the robot trying out the new FH form. Playing with a real person is very different, the much quicker speed of the returned ball plus the variations in spin, pace, and placement makes it so that I can't just focus entirely on the new form. It took a bit of time to start incorporating it into all my strokes, and I had some surprising findings.
First, the muscles activated were a but different than I thought. I immediately felt my left hip getting more work, this is surprising as the right hip is the one activated during the swing. Turns out that due to the increased right to left rotation, I had to use my left hip more at the end of the swing after the weight is transferred to my left side in order to stop the swing and recover. Secondly, my abs and back muscles were sore (in a good way), as this stroke as a whole activates my core muscles significantly more. Thirdly, when I really put power into it, I feel much more stress in my right ankle as it turns and then kicks off.
Second, I found that my shot now has naturally a bit more brush, and a bit less sidespin. I had to do some trial and error to find how to get a thicker contact. If I change nothing else except with the new form and a thicker contact, the ball just shoots way out. By the end of the session I could approach the consistency of my previous stroke, but it's not quite there yet. The less sidespin is also a bit surprising. I think this is because previously I had to do more rotation with my shoulder/arm, swinging it around, so that motion imparts sidespin to the ball. Now that I'm using my body to do the rotation my shoulder/arm can aim more forward, resulting in less sidespin, but increased topspin. My partner had more trouble blocking my shots, sending a lot of them long, I think due to the increased topspin.
Third, I found that this motion was more applicable to more situations. I've been having issues with balls that are returned a bit higher than I expect. I often had to lift my elbow to loop it back, which is bad form and leads to inconsistency. I tried fixing it with my stance, adjusting up and down, but when the ball comes quick that's not fast enough. Turns out, with this form, I could loop those balls just fine, with excellent consistency and no intentional adjustment. It's no issue dealing with lower balls either.
For the BH practice, I also made some nice discoveries. I've found myself whiff on the ball quite often when I try to amp up the power. When I don't whiff, I felt that I was often hitting with the trailing edge of the racket, or brushing a lot more than I intended. I tried a number of ways to fix that, different timing, lowering my starting racket position, going more forward with the stroke, different racket angles, etc. and nothing really helped. Turned out the fix was the easiest and most obvious one -- just try to hit the ball higher up the racket. I used the "overcompensate" method and tried to hit the ball with the leading edge of the racket instead, and all of a sudden the contact dramatically improved. I was launching BH drives with unprecedented power and consistency, and it felt sooooo good. It did lead to a few balls hit by the racket edge, but overall consistency was vastly better.
