水平位移
Also known as: 惯用臂侧走位, 手套侧切, 水平移动
水平位移是指一记球因旋转而产生的横向移动，以英寸为单位测量，向投手惯用臂一侧为正值，向手套一侧为负值。
与IVB类似，水平位移是在剔除无旋转球本身自然漂移之后测得的。沉球和二缝线速球带有正值（惯用臂侧）的水平位移；卡特球和滑球则带有负值（手套侧）的位移。水平和垂直移动的组合决定了一记球的“形状”，也被用来搭配能够良好隧道化的球种组合。随着追踪数据让移动特征变得可操作，具有极端水平走位的球种——水平位移超过15英寸的横扫型滑球——已变得越来越突出。
Learn to read your own horizontal break by pitching in front of a camera set up directly behind the pitcher and watching how far each pitch drifts laterally from the expected straight-line path to the catcher's glove.
Plot your arm-side and glove-side pitches on a movement chart and identify which pairs create the widest horizontal separation at the plate. This means those are your most effective two-pitch tunnels for maximising lateral stress on the hitter.
Example — 在追踪系统报告中
他的横扫滑球显示出17英寸的水平位移，当打者以为会打到速球、实际却面对一记横向偏移了一英尺半的球时，制造了挥空。
How it shows up on video
Horizontal break is visible on video as lateral movement away from the expected straight-line trajectory. A sweeping slider's break is observable to the naked eye in the final 20 feet of flight. Common errors affecting horizontal break include a spin axis that is too vertical (converting horizontal break potential into IVB), uneven grip pressure that produces varying amounts of side-spin between reps. A shortened delivery that reduces the distance the ball travels and therefore the total movement accumulated before the plate.
Common mistakes
- Confusing total spin rate with horizontal break potential. This means a pitch can have high RPM but poor horizontal break if the spin axis is oriented vertically rather than laterally
- Locating an arm-side breaking pitch at the inner edge against same-handed hitters where the movement direction runs toward the plate rather than away from the swing path
- Maximising horizontal break at the expense of vertical break. This produces a pitch that stays at one height and moves only laterally. This means giving hitters a predictable plane to hunt in the zone
- Throwing high-horizontal-break pitches from uneven arm angles. This changes the movement direction and makes it impossible to locate the pitch reliably to the intended zone edge
In SwingVantage Motion Lab
SwingVantage measures lateral trajectory deviation across rep sequences and plots horizontal break magnitude on a pitch-shape chart alongside IVB. This gives pitchers a visual representation of their full movement profile. The system identifies whether horizontal break is stable across a session or drifting. This means which can indicate grip fatigue or mechanical uneven results in the wrist and forearm.
Related terms
- 诱导垂直位移（IVB）诱导垂直位移是指一记球仅因旋转而产生的垂直移动，以一颗假想的无旋转球作为参照进行测量——将马格努斯效应从重力中分离出来。
- 滑球滑球是一种带有横向移动和些许下坠的变化球，比曲球更快，且后段变化往往更为锐利。
- 卡特速球卡特球是一种带有较晚手套侧移动的速球——比滑球更快，变化幅度比滑球更小——能顶住或躲开打者。
- 二缝线速球 / 沉球二缝线速球沿两条缝线握球，通常向投手惯用臂一侧并向下移动，容易制造滚地球而非三振。
- Seam-Shifted Wake (SSW)Seam-Shifted Wake（缝线偏移尾流）是一种空气动力学效应：偏离中心的缝线朝向会不对称地扰乱气流，从而产生仅凭转速或转轴都无法预测的球路移动。
- 转速（投球）转速是指球离手后每分钟旋转的圈数（RPM）——转速越高，马格努斯效应越强，球的移动幅度也越大。
Related guides & benchmarks
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