Trying to learn proper technique in racketsports such as tennis and badminton can be tough. Having an aid like the strangely named Holy Pie Smart Racket, though, can help curb a newcomer’s mistakes or refine a ...

The Premise. The best tennis technique involves not only a firm grip and good racket, but also a spin on the ball itself. This spin allows the ball to move in an arc, which makes it easier to get over the net. It ...