Currently at #6 in the world, Li Na of China is better positioned to inspire hundreds of millions of brand new tennis players than anyone else might ever have been. Don't be surprised if, not too long from now, you're seeing Li Na's Strokes reflected in a whole generation of young Chinese players.

A quiz is a great way to find out what you do and don't know, and for intermediates, there's usually an uneven mix. The topics in this Tennis Quiz for Intermediates include strokes, tactics, and rules.

Photos illustrate this step-by-step lesson on how to hit the topspin-slice (often called "slice") serve. Among advanced players and stronger intermediates, this is the most common first serve and the most powerful serve with reasonable reliability.

Roger Federer's backhand has always been his most attackable shot, but it has improved quite a bit over the last few years. Here's how Roger hits his backhand at different heights of contact and with different spins.