Recreational tennis players have no way to track their improvement objectively — they feel stuck but don't know what to work on

You have been playing tennis for 3 years. You feel like a 3.5 player but you are not sure. Are you improving? What specifically is holding you back? Is it your serve (you double-fault 3 times per set)? Your backhand (you hit it long under pressure)? Your net game (you never come to net because you get passed)? You have no data. You only have feelings: 'my backhand feels off today.' Your coach says 'work on your footwork' but that is every coach's default advice. Without objective measurement, you cannot prioritize improvement. So what? In every other sport with technology, athletes at all levels have data: runners track pace/distance (Strava, Apple Watch), golfers track handicap/launch angle (Arccos, Trackman), cyclists track power/cadence (Zwift, Wahoo). Tennis recreational players have nothing. SwingVision and Playsight provide shot-level analytics but require setup, subscriptions, and hardware that 95% of recreational players will not use. The result: recreational tennis improvement is guided by feel and anecdotal coach feedback, not by data. Players plateau because they practice the wrong things — spending an hour on forehands when their serve is the real problem. Why does this persist? Tennis analytics requires tracking ball trajectory, player position, shot type, spin, and outcome simultaneously. In professional tennis, Hawk-Eye costs $100K+ per court. Consumer solutions (SwingVision) use phone cameras and AI but require the player to set up a phone, which breaks the casual flow of a recreational game. Nobody has built a 'Strava for tennis' that is zero-setup, zero-friction, and provides long-term improvement tracking. The wearable approach (smart racket sensors like Zepp, Babolat Play) failed commercially because they tracked racket speed but not shot outcome.