Intermediate

Rollover (rouler les poignets) (rolling over)

Also known as: rollover, rollover précoce de la main du haut, roulant faible

Definition

Le rollover est un défaut de swing où la main du haut tourne sur la main du bas trop tôt, fermant le barrel à travers le contact et produisant des roulants faibles vers le côté tiré.

Dans un swing sain, le barrel reste carré (paume vers le haut / paume vers le bas) à travers la zone de contact et les mains roulent après que la balle est partie. Quand la main du haut roule tôt, elle entraîne le barrel vers le bas et autour de l’extérieur de la balle, imprimant du lift et créant des roulants côté tiré. Le rollover est souvent déclenché par un retard sur le lancer (compensé en forçant le swing), par une mauvaise trajectoire des mains ou par un calage de hanche qui force les bras à terminer le swing. Il est courant sur les balles rapides intérieures quand le frappeur est pris à contre-pied.

Beginner tip

Practice "palm up" contact by placing your bottom palm upward through the contact zone during slow-toss drills — if your palm flips downward before the ball leaves, you have identified the early rollover moment.

Advanced note

Review your rollover rate data by pitch location — rollover on inner pitches is usually a timing cause that requires a contact-point adjustment. Rollover on outer or middle pitches is usually a path cause that requires a hand-path fix, and treating them the same way will improve one while ignoring the other.

Example

Elle a frappé six roulants d’affilée vers l’arrêt-court — la vidéo a montré sa main du haut rouler avant le contact sur chaque lancer, un défaut combiné de timing et de trajectoire.

Why it matters

Rolling over can come from timing or from your swing path. The fix has to target the right variable: drill timing when you are out front, and drill the path when the swing works over the top of the ball. Motion Lab flags hips that stop turning, one common cause.

How it shows up on video

On video, rollover is identified by the orientation of the back hand at the moment of contact — if the palm is facing down or sideways rather than up-and-toward-the-pitcher at contact, the top hand has already rolled. Common visual signatures include the bat head arriving at the contact point already past parallel with the ground (barrel drooping due to rollover), grounders that reliably shoot off the bat end toward the pull-side infield gap, and the back elbow dropping below the back hip at contact rather than staying above it through the swing.

Common mistakes

Allowing the top hand to dominate the swing from the very beginning. A top-hand-led swing inherently rolls over because the top hand's natural motion is a pronation that drives the barrel downward
Responding to being jammed by muscling the swing over with the top hand. This produces the rollover pattern that causes a grounder rather than the checked swing or foul ball that would be a better outcome
Using a bat that is too heavy or too long. This causes the hitter to begin rolling the wrists earlier in the swing to control the bat's momentum before contact
Neglecting hip rotation as the rollover fix. Many rollovers are caused by hips stalling and the arms compensating with a muscled finish that triggers the premature top-hand roll

In SwingVantage Motion Lab

Motion Lab does not see your hands or wrists roll at contact. It does flag hips that stop turning, one common cause of rolling over, so check the top hand on your video.

Open Baseball in Motion Lab