Curing the Flat Backhand and the Modern Topspin Backhand
There's an 11-year-old I've been coaching for a while who hits his backhand extremely flat. It's become the biggest problem in his game - it often comes out almost as backspin, often spraying off the end since there's no topspin to pull it down. I've tried for months to get him to put a little topspin on the ball by starting with the racket a bit lower and slightly closed, but to no avail. His sponge was medium fast, but not a modern looping sponge, more of a hitting sponge, which seemed appropriate since he was primarily a hitter on the backhand. (He does have a backhand loop against backspin.)
The sponge was going somewhat dead, so I lent him a sheet of a used looping sponge. His first few shots went off the end. Then he adjusted by closing his racket more, meaning he hit more on top of the ball - instant topspin!!! It was a simple as that. Later, when I fed him multiball, his backhand loop was also vastly improved.
You can put topspin on the ball with a hitting sponge, but the looping sponge made him do so, leading to a much better backhand. While he doesn't need the most high-end (i.e. most expensive) looping sponges, it's becoming more and more important for players to use modern looping sponges even if you aren't using it primarily to loop. They are just bouncier, and make it easier to rally at high speeds.