Beginner

内飞球（打击）

Also known as: pop-up, sky ball

Definition

内飞球是一种带有极强后旋、发射角极陡（超过50°）的击球，几乎笔直向上飞起，几乎总是会被接杀出局。

内飞球是棒头在球心以下位置完成接触所致——下劈式的挥棒路径打在球的下三分之一处。较高的内飞球率与“先下后上”的挥棒路径、蓄力时手位过低、棒头在好球区内急剧下劈，或攻角相对来球高度过于向下等因素密切相关。由于内飞球几乎从不形成安打，它是打击数据中破坏力最强的结果模式之一。降低内飞球率与更高的打击率之间存在稳定的相关性。

Beginner tip

During tee work, set the tee at shoulder height and practice keeping the barrel parallel to the ground through the contact zone rather than driving the barrel down at the tee — parallel barrel paths at shoulder height produce the flat-to-slightly-upward approach that eliminates most pop-ups.

Advanced note

Compare your pop-up rate data on high fastballs versus low changeups — if pop-ups cluster on high pitches but not on low ones, your load position or attack angle is the cause. If they occur across all pitch heights, the barrel path angle is the issue and requires different corrective work.

Example

她连续三次把速球打成内飞球——录像显示她的棒头在好球区内急剧下劈，在球的赤道以下位置完成接触。

Why it matters

A steep, dropping bat path causes pop-ups long before the pattern shows up in your statistics. Motion Lab estimates your attack angle from your arm movement, so you can work on the path before the results confirm the fault.

How it shows up on video

On video, pop-up mechanics are visible in the angle of the barrel relative to the ground at the contact point. A barrel that arrives at a steep downward angle will almost always make contact below the ball's equator. Common error signatures include the back shoulder dropping significantly lower than the front shoulder at contact (creating a severe tilted plane that drives the barrel under the ball), the barrel tip pointing toward the ground at contact rather than remaining on the pitch plane, and the hands finishing above the head in the follow-through (indicating the barrel drove severely upward after undercutting the ball).

Common mistakes

Dropping the back shoulder sharply in an attempt to "lift" the ball. This paradoxically causes the barrel to undercut the ball more severely and produces higher pop-up rates than a flatter swing would
Setting up with low hands at load. This forces the barrel to travel upward to reach the high-pitch contact zone and produces steep undercutting contact on fastballs in the upper third
Confusing the launch angle goal (positive launch angle, ideally 10–25 degrees) with the barrel path approach angle (which should match the pitch plane, not arc upward toward it)
Over-correcting for a ground ball problem by exaggerating upward barrel angle. This shifts the contact window from the ball's equator to below it and trades a ground ball pattern for an equally problematic pop-up pattern

In SwingVantage Motion Lab

Motion Lab estimates your attack angle and swing-plane tilt from your arm movement. It does not track the ball or the pitch height, so it cannot link a swing to a pop-up; check the result on video.

Open Baseball in Motion Lab