The specifications of a tennis racket play a large part in how the racket performs. Different specifications suit certain players better than others. Two of the most important racket qualities are the stiffness and balance of the frame. Both significantly impact the playability of a racket.
Racket stiffness measures how much a racket flexes on its longitudinal axis. The stiffness is measured in RA, and most rackets fall between 55 and 72 on the scale. RA simply stands for stiffness rating. It is measured by placing a specific amount of weight on a lever, which bends the frame. Lower numbers indicate more flex; higher numbers indicate less flex. The stiffness of a racket directly affects the power of the frame. Stiffer rackets return more of the impact energy to the ball, resulting in more power, while flexible rackets return less energy, resulting in less power. Stiff rackets tend to be harder on the body. Tennis elbow and other arm problems are often worsened by very stiff rackets. More flexible rackets provide a softer impact with less shock and vibration. This leads to less power, but more feel and control as the dwell-time on the string bed during impact is increased.
A racket's balance is a measure of where its balance point is. This statistic is important because it also suggests where the weight is distributed on a racket. Racket balance is usually measured in points head light or points head heavy. Points are equivalent to 1/8th of an inch. Therefore, a racket that is seven points head light has a balance point 7/8ths of an inch below the midpoint of the racket.
Head Light Rackets
Head light rackets have most of their weight distributed toward the handle. They are generally more maneuverable by a player despite having high static weight. Head light rackets do not provide additional power, as most of the weight in the racket is distributed away from the hitting zone. Most professional players use head light rackets. Head light rackets are considered better for volleying because they are easy to maneuver at the net.
Head Heavy Rackets
Head heavy rackets have most of the weight distributed toward the head of the racket. This type of racket feels heavy in the hand despite usually having a low static weight. Head heavy rackets provide additional power because most of the weight in the racket is in the hitting zone. Few professionals use head heavy rackets, but this type of racket can help smaller or weaker recreational players generate easy power.