不合法投球
不合法投球是指任何违反规则的出球——最常见的是弧线超出合法窗口、故意加转的投球,或从不合法位置出手的投球。
慢投中常见的不合法投球违规包括:弧线过低(低于6英尺)或过高(超过12英尺);出手时故意施加旋转(出手时猛烈转动手腕);双手出手;或者从胶皮以外的位置投球。当被判定为不合法投球时,击球员可以选择将其视为坏球,或者选择挥棒击打。投手会学会读懂裁判的判罚倾向,并把弧线调整到位,以保持合法并保护球队不因此被白送球数。
If an umpire calls your pitch illegal, ask in particular which rule was violated. This means arc, speed, or release. This means. As a result, you can fix the correct issue rather than changing the wrong thing.
Film your practice pitches from the side with a reference marker at 6 and 12 feet to build a visual library of your arc heights across different speeds and effort levels.
Example
投球升高到14英尺——远超最高限制——裁判立即示意“不合法投球”,判给击球员一个坏球。
How it shows up on video
An illegal pitch is identifiable on video by comparing the ball's peak height against a known reference. This means a flat delivery that never visibly rises above the batter's helmet is almost certainly below 6 feet. A spin-enhanced pitch shows rapid rotation visible as a visible seam blur or an unusual lateral curve that a standard arc would not produce. The umpire's call is definitive, but video review helps pitchers self-diagnose between games.
Common mistakes
- Throwing too hard and flattening the arc below 6 feet in the excitement of a key at-bat, the most common illegal-pitch type in competitive slow-pitch
- Adding wrist-snap to generate extra spin for movement, not realizing the association classifies intentional spin as an illegal pitch
- Failing to come to a complete stop with both feet on the rubber before starting the delivery. This some associations classify as an illegal start position
- Pitching from the wrong distance after moving to a different league, unknowingly using 46-foot mechanics from a 50-foot rubber or vice versa
In SwingVantage Motion Lab
SwingVantage can flag pitch deliveries where the estimated arc height falls below the 6-foot threshold from video analysis. This gives pitchers objective feedback to self-correct before a game situation.
Related terms
Related guides & benchmarks
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