Don Mueller is on a lonely crusade to promote two-racquet tennis 

Dr. Mueller dives into tennis with both hands. He uses two tennis racquets, one in each hand, to give lessons.

So does Dr. Don Mueller charge double for those lessons?

It is a joke, of course, and Mueller laughs right along because he is accustomed to people belittling his ambidextrous version of the grand old game. People don't get it, especially the purists who think he is making a mockery of tennis. Mueller, 46, shrugs off the ridicule because he has three things to share with his two racquets and those things are important to him: the fun of two-handed tennis, physics and physical fitness. A physics/chemistry/math professor -- he always seems to do more than one thing -- at area colleges in New York and New Jersey, Mueller picked up a second racquet with his right hand three years ago and started having fun. There are some important things to learn about two-handed tennis, he says. Elbow injuries in tennis can occur with the backhand return more than the forehand return. With a racquet in each hand, a player uses only forehands and reduces the risk of injury.

"You have replaced your backhand with a powerful forehand," Mueller said, "and I don't know anyone who can hit a backhand harder than a forehand."

He can save motion by tossing the ball in the air using one racquet and hitting it with the other. Mueller's wingspan, naturally, is double the width because he can spread himself wide with two racquets. If you have a bad back, no problem, just use the two racquets to pick up the ball without bending over.

How does he run? "With my legs," Mueller says incredulously. "Holding two racquets does not slow you down."

Mueller's method has been challenged by tennis players who think they know better. "One guy said in an e-mail that he would just hit the ball right back at me if I came to the net," Mueller said. "Well, I would just put my racquet up in front of my face, either one. You don't have to hold it as if to hit a forehand all the time."

Mueller's study of physics can provide a lesson or two for the tennis player. He said Andy Roddick, a tennis pro, can launch a serve 140-150 miles per hour, but opponents should not be daunted because that's the speed when it leaves Roddick's racquet. Mueller said the ball is closer to 75 miles per hour when it reaches the player on the other side of the net.

"I play two-handed tennis against two people with one racquet," Mueller said. "I can put the ball in places they can't get to. I win."