I recently had the pleasure of hosting legendary coach Nick Bollettieri as the featured speaker at my annual High School Coaches Clinic. Nick is an engaging speaker and his record of elevating the most gifted athletes to great heights is unmatched.
Nick Bollettieri, like all great messengers, is inspirational and an extraordinary leader. Leadership can take many forms; however, wisdom based upon a deep understanding of theoretical knowledge is often the fastest and safest road to improvement, especially when laying the groundwork for future development. Coaching tennis is the synthesis of art and science, and the science behind this art is the foundation of most sound coaching.
While many believe that Nick is the best "coach" in history, the world's best tennis "instructor" does not have an academy named for him, nor has a "system" (a laughable way pros describe their work on social media to make themselves appear more substantial), and has never even hit a tennis ball. If you don't know and use his work as a guiding principle to understand tennis, you are making an unforced error.
Isaac Newton is the founding father of modern sports instruction, because he is the originator of the physical laws of motion, and we live and play in an ever-moving physical world. Coaches may debate best practices all day long, but Newton's ideas are laws, both universal and immutable.
Below are my top five favorite instructional ideas based on principles of (mostly) Newtonian physics.
1. A student recently asked me my thoughts on the following bit of instruction he heard given to a group at a well-known academy. The coach asked the group the following question: "Since most coaches say that power comes from your legs. If this is true, how is it that wheelchair athletes can serve within 15 percent of the speed of able-bodied athletes and they don't have use of their legs?" His conclusion was, "Power therefore comes from your upper body." Of course power does not come from your legs or any other body part. Instead, power comes from the ground and is transmitted through your body. It doesn't really matter if it is your feet or your wheels on the ground (except that you can load your legs with greater elasticity—see Hooke's Law). Newton's third law of equal and opposite force says it clearly, “Force comes from pushing into the ground and from the ground ‘pushing’ back.”
2. How low should you go to load? I hear instruction all the time focused on the "lower the better," but getting low comes at a cost: Greater gravity. Therefore, it's not a big drop, but a quick and well-timed dip, almost like taking your foot and thinking of pressing a button on the ground that will get the job done best. Power starts with a quick, elastic push into the ground that stores energy, and an explosive, yet efficient, release.
3. Balance is the most important quality in tennis or so I'm told, and we all know it when we see it. But to teach balance, you really need to understand balance. Here is a simple explanation. Newton's first law states that: "A body in motion stays in motion, a body at rest stays at rest unless acted upon by an unbalanced force." In the physical world of tennis, balance as we recognize is achieved by exerting a force equal to gravity, or achieving zero acceleration in movement. In the most practical of terms, balance is enhanced by displaying no change in movement velocity. Since the goal of striking a ball is to gain speed, a most stable body is needed to counter the unbalanced strike force. So don't change the speed of your foot movement while you accelerate your racket to stay balanced while displaying power. You got all of that? There will be a test at the end of this article.
4. The net is lower in the middle, so aim to hit over it and you will make more shots. Right? Well … not so fast. Howard Brody, Professor of Physics at The University of Pennsylvania in his book, Tennis Science for Tennis Players, points out that while the net is lower, it is also further away and these two factors cancel one another out since cross-court and down the line net areas have the same ball trajectory acceptance angles. Think of it this way … if you are shooting a basketball into a net from 12 feet away, the arc of your shot (all other factors being equal) will need to be higher than a shot from 10 feet away. Lower the net to let's say nine feet high from 12 feet away and you can now have the same arc as the 10 foot shot to the 10 foot basket.
5. The faster your racket swings, the faster you will hit so I hear. Again … not that simple. "The Trampoline or Spring-Like Effect "says that the force of the swing must match the depression or elasticity of the ball, strings and racket or much of the energy created from the strike will be lost making a faster swing so inefficient that it will have little effect on the work performed. Power is more than speed. Power is the result of greater energy applied to the hit.
Ultimately, players don't need to understand the science behind their skills. Ask Nick Bollettieri and he will tell you, "Just hit the damn ball!" Such advice for high-performance is sometimes this simple and can be highly effective. Coaching for skill development is different, however, in that it requires instruction based on a deep and clear understanding of how the physical world works. A knowledge of physics encourages coaches to filter and simplify information into practical teaching cues to ensure that students progress safely and quickly.
Steve Kaplan is the owner and managing director of Bethpage Park Tennis Center, as well as director emeritus of Lacoste Academy for New York City Parks Foundation and executive director and founder of Serve & Return Inc. Steve has coached more than 1,100 nationally-ranked junior players, 16 state high school champions, two NCAA Division 1 Singles Champions, and numerous highly-ranked touring professionals. Many of the students Steve has closely mentored have gone to achieve great success as prominent members of the New York financial community, and in other prestigious professions. In 2017, Steve was awarded the Hy Zausner Lifetime Achievement Award by the USTA. He may be reached by e-mail at StevenJKaplan@aol.com.