The follow-through is the one part of the swing hitters treat as decoration. It isn't. It's a receipt — proof of what happened before it. A swing that drove all the way through the ball wraps up high, over the shoulder, because all that momentum has to go somewhere. A swing that quit at contact stops short, hands down near the chest. You can read the whole swing backwards from where the hands end up.
A full finish is earned, not posed
You can't fake a good finish by reaching for it after the fact — the finish is a result. If the swing drove through the ball with a firm front side and full extension, the barrel's momentum carries the hands up and around on its own. If the swing cut off, folded, or rolled over, the hands run out of gas and stop low. So a short finish isn't the fault itself; it's the tell that the drive through the ball came up short.
That's why chasing the finish directly rarely works, and fixing the drive fixes the finish for free.
What the camera reads
CoachVision measures your finish height — where your lead hand ends up relative to your lead shoulder — on both camera angles. Wrapping at or above the shoulder is the natural end of a full turn; a finish stopped down at the chest (a negative read) is the cut-off swing. It's read off the lead (bottom) hand on purpose, because the top hand often releases in the follow-through — so a one-hand finish is completely normal and not a flaw. Don't let anyone tell you a released top hand is a problem; the app expects it.
It travels with extension through the ball: a low finish and a short extension are the same cut-off swing seen at two moments. Read them together and you've got the whole story of the back half of the swing.
The honest note: "contact" is your hands' speed peak and the camera can't see your bat — so this reads where your hands finish, not your barrel. And a clip that gets cut off right after contact will read the finish as truncated: that's the camera stopping early, not you quitting early, so hold your finish a beat when you film.
The fix — drive through, and the finish follows
High-Tee Line Drives: a tee at the top of the zone, hit hard on a line. Lining out a high tee demands you drive through the ball — and a swing that drives through finishes high automatically. Ten balls, thinking "hit it back through the pitcher," and let the finish wrap up on its own without reaching for it.
Film one swing — and hold the finish a beat so the camera catches it — check your finish height, then ten high-tee line drives a round until the receipt reads "drove all the way through."