Originally Posted by JohnYandell
If you look at video there are several hitting arm configurations which explains the variety of thinking above.
Agassi and Nadal are straight/straight at contact. This version requires at least a mild backhand grip with the bottom hand. If those two guys let go with the rear hand you could imagine them hitting a flat, mild continental grip flatish one hander with ease.
Most women (and some men) are at the opposite extreme. Bent/Bent. The top arm looks like a double bend forehand. The bottom are is also bent around 90 degrees at the elbow Some of these players--Venus for example--have a grip shift with the bottom hand that probably doesn't rise to the level of even a slight continental--more like an old style eastern forehand--think Don Budge. This version is the most left arm dependent.
Most men like Djok or Andy are Bent/Straight. This version relies on the bottom arm to initiate followed by a push with the top arm. These guys all have continental to mild eastern grips with the bottom arm. Makes sense because the initial pull is critical. Roddick's big weakness was his backhand was Bent/Straight but he had a very weak (Venus like) grip with the bottom hand.
All of these combinations are viable at all levels--it's some combo of natural inclination and correct technical input.
Do you think that the Windshield-Wiper-finish double bent 2hbh like Wozniacki's here will be the next evolution in 2hbh?
Wozniacki, unlike Venus, hits most from a closed stance, but I'm assuming she could hit from an open stance, in which case the evolution to a left-handed forehand would be complete - an open stance, double bend, windshield wiper finish stroke. I'm assuming you'd use a weak bottom hand grip like a right handed eastern forehand grip, and a strong bottom grip like a lefthanded sw or w forehand grip.
Interestingly, the straight/straight combo can also produce a windshield-wiper finish like with Nadal and Courier. Here's Nadal doing it;
although he doesn't finish as low as Wozniacki... I'm assuming for this style you'd use a strong bottom hand grip like a right handed full eastern backhand grip, and for the top hand a strong grip like a sw or w left handed forehand grip...
EDIT: I'd also love it if you could share any more topspin backhand rpm data from anyone on either mens or womens' tour?