Ace Trace

Ace Trace turns a phone clip of one tennis stroke into 17 tracked body points, six labelled phases and a coaching report. It is built for tennis academies, coaches, players and parents, and it works from any phone at any angle: no sensors, no lab.

How it works

• Film: record one stroke and choose the stroke type, stance and dominant hand, so the right phase profile loads.
• Extract: Google's MoveNet model tracks 17 body points on every frame, in the browser on the user's own device. The video does not have to upload; only the skeleton's coordinates do.
• Phase review: the start of each phase is detected from wrist speed, racket drop and the toss peak. The coach confirms or nudges each one.
• Compare: each phase is lined up with the same phase of a professional baseline, mirrored for left or right handers, and scored on joint angles, rotation, balance, contact and speed.
• Report: checkpoints in range, the top corrections, injury-risk flags, and strengths, issues and drills per phase. The words come from the measurements and the coach's own notes.

Built to be checked

Every number in a report can be traced back to the skeleton that produced it. The scoring is simple on purpose: each phase starts at 100 and loses points for how far it sits from the baseline, with contact and acceleration weighted most.

• The professional baselines keep the pose data and drop the video.
• Each academy can set its own target ranges for every joint angle.
• A minor's video, body measurements and coach visibility need a parent or guardian's consent before anything runs.
• Honest limits: one stroke per clip, multi-swing clips are turned away rather than blended, and contact timing is only as precise as the frame rate.
• Each academy is its own tenant, kept apart from the others.

Who it is for

• Academies: run coaches, players, courts and billing from one place.
• Coaches: review a roster's strokes and confirm phases in seconds; their notes shape the report.
• Players: their own history of strokes and feedback.
• Parents: their child's progress, and the consent controls.