Half-step late? Paddle wide open? Feel it the instant it happens, not after you've already lost the point. Beginner or 4.5, doesn't matter.
Snap two sensors onto the net posts. That's it.
Shoes, paddle, done. Nothing to charge mid-game.
Start rallying. It's already watching.
Foot fault? Feel a buzz before your next step, while your body still remembers what it just did.
Coaching tips land between points. Never once during one.
See exactly which rallies your feet and hands stopped agreeing with each other.