In the simplest of terms, a wider racquet is going to give you more power. This racquet is usually also stiffer and returns more energy to the ball, thus giving you more power with the same swing. A thinner racquet is usually going to be more flexible and not do as much of the work for you. This means that you have to swing harder to get more power. In addition to those factors we have head size. When all other things are equal, a larger headed racquet will provide more power than a smaller one. So after reading all of this you are probably thinking, "why shouldn't I go for the thick beamed, oversize racquet?" The answer is it might not fit your game or your swing.

The general rule of thumb is this... The longer and faster you swing, the more flexible racquet you should be using, and the shorter your swing the stiffer racquet you should be using. Flexible racquets normally have smaller head sizes (less than 100 square inches), while stiffer frames tend to have larger heads (greater than 100 sqare inches).

So if you are the type of player that takes a big, full swing at the ball, using a 9 ounce, 125 sq. inch racquet is probably not the best move. On the other side, if you punch the ball around from the baseline, you are not going to help your game by purchasing the new Wilson [K] Pro Staff.

So size does matter... At least as far as tennis racquets go...