Intermediate

Lijndrivepercentage

Also known as: LD%, linerpercentage

Definition

Het lijndrivepercentage (LD%) is het percentage geslagen ballen dat als lijndrive wordt geclassificeerd (doorgaans 0–25° lanceerhoek met hard contact) — het type geslagen bal met het hoogste verwachte slaggemiddelde.

Lijndrives hebben het hoogste verwachte slaggemiddelde van alle types geslagen ballen, omdat ze hard geraakt worden, lang genoeg in de lucht blijven om veilig te landen, en lastig te vangen zijn. Een elite LD% wordt over het algemeen beschouwd als 25% of hoger. Slagmensen kunnen hun LD% verbeteren door het kopspad langer op de werpbaan te houden, rollover te verminderen en de attack angle beter te laten aansluiten op de neerwaartse baan van de bal. LD% is over kleine steekproeven een stabielere indicator van echte contactkwaliteit dan slaggemiddelde.

Beginner tip

During tee work, focus on hitting the back half of the ball. This means the part furthest from the pitcher. This means and drive it straight back through the imaginary pitcher's mound. This produces the contact geometry that generates the highest line drive rate.

Advanced note

Compare your LD% data across pitch velocity bands in your SwingVantage session reports. This means a significant LD% drop on high-velocity pitches confirms a timing cause. A consistent LD% decline across all pitch speeds confirms a barrel-path or contact-point cause that does not depend on timing.

Example

Haar lijndrivepercentage van 28% was de duidelijkste indicator van haar contactkwaliteit — ze kwam consequent overeen met de werpbaan en raakte de bal vierkant.

Why it matters

SwingVantage's analyse van kopspad, attack angle en contactconsistentie sluit rechtstreeks aan bij de mechanische aanjagers van het lijndrivepercentage — verbeteringen in de analyse vertalen zich naar echte verbeteringen in de kwaliteit van geslagen ballen.

How it shows up on video

On video, line drive production is associated with a barrel that arrives at the contact point on a matching plane to the pitch trajectory. This makes contact at or slightly above the ball's equator. Common errors that suppress line drive rate include a barrel arriving below the pitch plane (undercutting. This produces pop-ups), a barrel arriving from above the pitch plane (chopping. This produces grounders). A barrel arriving after the optimal contact zone with the arms still bent (producing weak, pull-side flares rather than hard-hit drives).

Common mistakes

Confusing line drives with "contact hitting" and reducing swing aggressiveness in an attempt to make more contact. This means line drives require hard barrel contact, and pulling back swing intensity produces soft grounders and flares rather than true line drives
Using a barrel path that is too flat or downward across all pitch heights rather than adjusting attack angle to match specific pitch locations. This means middle-height pitches need a flatter approach than low-in-the-zone pitches
Treating LD% as a random outcome rather than a mechanical metric. This means over a sufficient sample, LD% is one of the most mechanically stable statistics available and should be used as a training target
Neglecting the attack angle dimension of line drive production and working only on barrel path without also verifying that the approach angle at contact is in the 10–25 degree window that produces true line drives rather than flat grounders

In SwingVantage Motion Lab

SwingVantage correlates barrel path angle and contact location on the ball's surface with batted-ball outcome categories. This builds a session-level line drive rate estimate from mechanical data alone. Pitchers see a suppressed LD% metric that quantifies how effectively their pitch movement and location is preventing clean barrel contact across rep sequences.