The pros aren't the only ones who have their tennis serves critiqued at the U.S. Open. Event sponsor American Express has a swing analysis station for fans who attend the tournament, which is played annually at the USTA Billie Jean King National Tennis Center in New York's Flushing Meadows.
The station, which is free to all visitors, is located within a venue that also houses another Amex-provided tech feature—a touchscreen court curator that provides match times, food recommendations and other information to help optimize each fan's experience at the tournament. However, the swing analysis station has the most innovative technology on site.
Via straps around a user's waist and over the shoulder of the serving arm, motion-capture technology apprehends four parts of a serve—approach, top of serve, point of impact and the finish.
The user serves into a net several times while a local tennis club pro observes the session. Data is fed from the straps to a nearby computer, which outputs digital readouts and screen graphics that provide a visual system for analyzing the four key parts of the serve. Graphics color-coded in green, yellow and red accentuate the arc of the user's arm and torso throughout the swing.
Craig Kardon, director of tennis at Centennial, Colo.-based GolfTEC Enterprises, which developed this form of analysis, explains why it is vital to measure the four selected parts of a serve. At the serve's point of address, he says, "you want the shoulders to be a little bit open, the body relaxed, feet shoulder-width apart and weight on the front foot."
The backswing leading to the top of the serve begins the loading phase. According to Kardon, that's when both hands are raised for the toss; weight shifts toward the back foot; and the racket is swung back, like the beginning of a baseball throw.
The top of the swing, also known as the "trophy position," is the peak of the loading phase. Kardon says that at the point of impact, when the racket hits the ball, the shoulders should be rotated up and the ball should be well inside the serving line. For the finish, the body should be square to the target, so the server can react appropriately to a return shot.
GolfTEC Enterprises has been using motion-capture technology since 1995. It was a featured attraction at the U.S. Open golf tournament in June. This is the first time the technology has been used for tennis.
Since it evaluates tennis players at all skill levels, the technology has to produce analyses that are easy to understand. "We want to keep it simple for a fan experience," says Steve Bauerle, vice president of business development for GolfTEC.
American Express, now in its 18th year as a U.S. Open partner, is giving its customers an extra benefit with a free ten-minute private lesson in the swing analysis area. An email with video, audio advice from Kardon and a set of recommended drills is sent to each user after his or her training session.
The email follow-up gives Amex customers a benefit that lasts longer than a brief tennis lesson. American Express and GolfTEC are attempting to satisfy U.S. Open attendees looking for added value for the price they pay to watch Serena Williams, Rafael Nadal and others compete at the world's biggest tennis tournament.
Photo: Terry Ratzlaff
Kyle Stack is a New York-based writer/reporter who covers health, technology, business and media in sports. He also writes for SLAM, Wired and ESPN. His work can be found at kylestack.com.