FAQ

How should I film?

Opposite batter's box, chest-facing, full body, phone propped still, landscape, 60 fps when you can. See How to film for the diagram.

Why only side view?

This preview only reads a chest-facing side view. Front, rear, and catcher views are marked unavailable.

What does the lab measure?

Front-knee brace, stride, hip-midpoint shift, and head drift as 2D side-view estimates against your own baseline.

What does the lab not measure?

Hip-shoulder separation, pelvis-to-trunk order, anything about the bat, forces under the feet, and launch-monitor numbers. See What we can't see.

Does the clip leave this device?

Analysis runs in this browser. The clip is not uploaded. Baseline numbers stay in local storage on this device.

What is the local nickname for?

It names the baseline on this device so you can keep more than one hitter without sending names to a server.

How does contact get marked?

From an isolated impact sound when audio is usable, from your tap on the timeline, or as an estimate when neither is available.

What does Founder Beta mean?

Experimental development preview. Estimates from 2D video. Not validated coaching.

Can youth hitters use this?

A guardian should supervise. Activate, Discover, and Progress keep side-view measurements and do not get a mechanical priority. Published lab context is hidden for those bands. Height stays on this device and is used only to decide whether to show the stride range as background.

Does softball use different formulas?

Softball uses the same locked phases and side-view formulas. Softball norms not sourced. Bat and ball differences are notes, not separate measurements.

What is a retest?

A later clip filmed with the same setup, compared with your earlier clips on this device. Verdicts are Improved, No clear change, or Can't tell yet.

What if the clip will not play?

iPhone HEVC often fails in desktop browsers. Use Settings > Camera > Formats > Most Compatible, or open this page in Safari.

Why only one priority?

This preview names at most one movement to train and pairs it with one drill. It does not rank hitters.

How is the baseline built?

The last few swings on this device, same nickname, sport, and handedness. Averages appear from three swings. Own-spread flags wait for six swings or a prior session. They are not a published cut-off.