HYROX Wall Ball Depth Checker

What the checker actually looks at

The checker does one thing, and does it well: it decides whether your hip drops below your knee on every rep — the depth standard HYROX judges apply under Rulebook 8.8. It reads the hip and knee points on your body frame by frame, finds the lowest point of each squat, and marks that rep counted, grey zone, or no rep.

That is a narrower question than 'was it a good rep', and deliberately so. A throw can hit the target and still be waved off because the squat was shallow — depth is the miss a target-focused eye skips, and the one no-reps pile up on once your legs are cooked. Read the depth column rep by rep and you know exactly which ones a judge would have taken away.

Film it so the read is honest

The read is only as good as the angle, and one rule matters more than the rest: film from the side, square to your body. A front or back angle hides the hip-versus-knee line the whole judgement rests on, so the tool cannot score it and tells you so.

• Side-on — the camera looks straight at the plane your hip and knee move in.
• Full body in frame — head to feet, standing through the bottom of the squat, or the standing reference the tool calibrates against goes missing.
• Phone at hip height, about 3 m away — level with the movement, far enough to keep you framed on every rep.

The clip is then walked frame by frame at up to 24 fps, so a fast rep at the bottom is not skipped between frames — the way a casual eye, or a phone scrubbing at real speed, slips past the deepest instant.

How a rep is scored

Every rep lands in one of three buckets, scored off how far the hip travelled past the knee at the bottom:

• Counted — the hip cleared the knee with room to spare.
• Grey zone — within about 5% of the line, either side. These count as valid, on purpose: a real judge gives a borderline rep the benefit of the doubt, and so does the tool.
• No rep — the hip stayed above the knee by more than the grey margin.

Each rep also shows a depth figure — how far past parallel you reached, as a percentage — so a 'grey' call is a number you can see, not a guess. Underneath, pose estimation (MediaPipe, 33 body landmarks) supplies the hip and knee positions the maths runs on; the judgement itself is plain geometry — the same hip-below-knee test a human judge makes by eye.

Where to trust it, and where to trust your eyes

Treat it as a sharp second opinion, not an official verdict. The call is only as clean as what the camera saw: a slightly high or angled camera compresses depth and can read a good rep as shallow, and loose shorts over the knee blur the exact line. When part of your body is hidden from the lens, the tool marks that rep low confidence rather than force a call it cannot back up — so a borderline grey rep filmed off-angle is a cue to re-film side-on, not a reason to argue with a judge.

On privacy there is no fine print: the analysis runs entirely in your browser. Your clip is read straight off your device, never uploaded, never stored on any server. Close the tab and it is gone — which is why the first run downloads the pose model (about 9 MB) once, so the work happens on your side instead of ours.