The most overlooked and under-taught factor for players trying to achieve their potential in tennis is relaxing the hands. Not only can players increase their control by relaxing their hands, but they can also enhance their ability to hit with power.

Tension makes a difference when striking a tennis ball, and, in fact, it is common to hear someone describe how easy tennis is in practice when there is no pressure compared to how difficult things become in stressful competitive situations. So, though it is important to learn the various components of good strokes, the problem remains that good strokes do not necessarily lead to playing well, and the gap between having good strokes and playing well can often be traced to excess tension in the hands. A related, though less overlooked, ­factor in achieving one’s potential in tennis is watching or tracking the ball. Martial arts have incorporated relaxation and awareness training for centuries, and tracking the ball and relaxing the hands are the tennis equivalent.

Roger Federer provides excellent evidence for the importance of these factors because he never looks like he is straining to hit a ball, and it is rare to see a photograph of him not looking at the ball. In fact, the only time that he seems not to be looking at the ball is when he is looking at the contact point where the ball just left his strings. ­Federer provides the perfect example of what it is to be relaxed while striking a tennis ball; to say that he is relaxed is not to say that he does not use any muscle tension at all, but instead that he uses only the tension that is required and no more.

More control
Many players instinctively know that if they squeeze their racquets as tightly as possible while hitting shots there will be less control than if their hands are relaxed. To demonstrate this more clearly, however, the following experiment can be used as an easy way to show how tension affects control. The experiment is to hit balls to a player’s forehand volley, but instead of the player hitting normal volleys, the player bounces the ball upward from the racquet in order to be able to catch the ball in the nonracquet hand. The player should volley using a tense racquet hand, and then a relaxed hand, and see and feel the different results. Generally, a tense hand will cause the ball to bounce higher off of the strings, while a relaxed hand will allow enough control to bounce the ball high or keep it lower. This drill can even be used as a test of skill given that highly skilled players can keep the bounce very low before they catch it, whereas beginners typically have more tension in their hands and therefore pop the ball much higher before catching it. This drill demonstrates more than just skill, however, in that it shows just how different a player’s results can be with exactly the same motion but different tension in the hands.

To help understand why extra tension can adversely affect control, imagine a runner stiffening all of the muscles in his legs and then trying to run. This would make movement difficult because flexibility and quickness decrease as tension increases. In fact, perfectly tense legs are completely immobile and inflexible.

More power
Having more control with a relaxed hand may be obvious to many, but it may be surprising to some that there is also more power to be had as well. It may be ­similarly surprising that boxers often discuss the feeling of a loss of power when they tense up in order to try to hit harder. This reinforces the martial arts saying that "power is in direct proportion to one’s ability to relax." The relationship between tension and a loss of power is primarily due to excess tension causing some muscles to work against others.

Furthermore, in tennis, power is only useful in relation to how well it can be controlled, and power is often associated with a loss of control. Remember, however, that with relaxed hands, control is enhanced, so an increase in control from having relaxed hands will also enhance the ability to control harder-hit shots. Power is achieved in tennis through accelerating the racquet, so the key, then, is to develop the ability to relax the hands while simultaneously swinging the racquet head very quickly. This can be accomplished by using the body’s kinetic chain to generate racquet head speed while still keeping the hands relaxed.

To suggest using the body for power while keeping the hands relaxed is to imply that the hands are not a significant source of power in themselves. Precise analysis of strokes goes beyond the scope of this discussion, but, in fact, a player who only uses the arms and hands for power would be quickly identified as someone with beginner-like strokes. Advanced strokes require the involvement of body parts other than the hands and arms to be able to play consistently with control and power. From the ground up, the legs, hips, and torso work together to create a motion that is capable of generating enough power that the hands and arms are not needed to generate power through independent motion. The hands, when they’re not tense, can be very powerful at the end of a series of linked motions.

Why relaxing the hands is often overlooked
When watching a touring professional strike a ball, one commonly sees how effortless and relaxed the motion seems, especially in comparison to an amateur player, but rarely does a relaxed hand stand out as a primary component of the professional’s smooth stroke. Similarly, it is often difficult for tennis coaches and instructors to see whether students’ hands are relaxed or not. This is made more challenging given that other—though often related—components of a student’s stroke seem to stand out more and so receive more attention.

In fact, relaxed hands and other aspects of good strokes are interconnected, and because of this, tennis coaches and instructors often see the bi products of relaxed or overly tense hands in other components of a stroke. For example, tense hands often lead to an abbreviated follow-through. Unfortunately, not only is relaxing the hands difficult to see, it is also a difficult topic to describe and make clear, especially to younger students, so, as a result, coaches and instructors often simply suggest a longer and more extended follow-through. While this advice is technically correct, the follow-through can be lengthened while the hands remain tense, so the result of the problem is addressed but not necessarily its source.

The feedback loop
To understand why seeing the ball clearly and relaxing the hands are so important, imagine a person’s brain as the control center of a feedback loop. The information loop begins when a player sees an approaching ball. That is, information about the oncoming ball is sent to the brain through the eyes. The brain processes the information and generates instructions for the body as to how to meet the ball and return it, and these instructions materialize in the body as subtle muscle tension and release. This is significant because there will be a problem if the muscles receiving the messages are already tense. If the muscles are already tense, the brain’s signals to the muscles reach a dead end—that is, the appropriate muscles cannot flex and release at the proper times because the muscles are already tense.

The brain also receives feedback after a shot has been hit. Following a shot, the brain receives and processes information from the body about the tension that was used while hitting a shot, and this information is combined with more information from the eyes about the success of that shot. This information will be stored in the brain and used to help determine how to best respond to future shots. In this way the brain creates a feedback loop of information from before and after a shot is hit, and from inside and outside of the body.

A tennis player’s general improvement is tied to the feedback loop. The brain makes the best decisions about how to signal the body when it has good information. Before the shot and from outside the body the best information is obtained from seeing the ball clearly. The brain is fairly good at tracking the ball even when a person is not watching carefully, so an important point to remember is that the brain receives better information the more carefully the ball is watched.

The best information after the shot and from inside the body comes from the hands being relaxed during the shot. If the hands are tense when the ball is struck, the brain receives this information about the tension and also notes where the ball goes after the shot. Using tense hands will impede improvement because extra tension confuses the brain’s ability to determine the most effective levels of tension. If the hands are more relaxed when the ball is struck, however, the brain receives much more precise feedback with regard to how much tension was useful, and the added precision speeds improvement.

Final comments
As mentioned, good strokes are intertwined with relaxing the hands. Beginners can learn to appropriately relax the hands at the same time they learn the basic fundamentals. For advanced players, there might be some unlearning to do in order to relax their hands properly. It may also be useful to know that different people learn to relax on different strokes at different rates. For example, it is common for players to learn to relax earlier for groundstrokes than for serves.

Regardless of the stroke, players should relax their hands as completely as possible with only enough tension to avoid dropping their racquets. Ideally a player should hold on to the racquet very lightly, as if holding on to a live bird, not so loose as to let it go, but no tighter than is necessary to keep it from flying away. Players should keep their hands feeling as relaxed as this throughout the entirety of their strokes. This is not to say that there will be no tension, but the tension will be very light and practically unnoticeable. Strokes with relaxed hands may seem softer at first, but with practice the results will be as hard as ever, and probably harder.

A racquet’s weight and grip size are potential factors in being able to keep the hands relaxed. Generally speaking, a good rule of thumb is to use the heaviest racquet that feels comfortable. One reason is that a heavier racquet provides more stability on off-center hits, and this will help to reduce twisting in a player’s hands, thereby requiring less reflexive stiffening in the hands on contact with the ball. Using an appropriately sized grip will also help to keep the racquet from twisting in the hands, and so will similarly help prevent unnecessary tension.

If a player has difficulty keeping the hands relaxed throughout a stroke, there may be a problem with the stroke itself. In fact, being able to relax the hands throughout a stroke is important evidence of the stroke’s stability. Examples of problems with a stroke that could impede the ability to relax the hands include late instead of early preparation, contacting the ball behind or next to the body relative to the net instead of meeting the ball out in front of the body, or using the arms for power instead of coiling the body for power.

Players should be taught to track the ball as carefully as possible until the ball is struck. Remember that tracking the ball is the important step that provides information to the brain and the rest of the body as to how much or how little tension is required. In fact, it is common for a person’s success level to go up immediately as a result of tracking the point of contact a bit longer than usual.

Ultimately, one of the best measures of skill and one of the most important facets of improvement is the ability to relax the hands while hitting strokes. If a player perceives any significant effort or tension in the hands while hitting any stroke, no matter how hard the player is hitting, then something is wrong. Perhaps something is wrong with the stroke, or perhaps the stroke is fine but the player is too tense. Either way, it is only when the person can hit hard with very little tension and perceived effort that the player’s potential can be reached.