合法出球
Also known as: 合法投球, 合法慢投出球
慢投垒球中的合法出球,是指以下手方式、经由平稳连续的动作投出,并以规定的弧线高度——通常在6到12英尺之间——越过本垒板的一记投球。
裁判从三个方面判断一次出球:出手方式(必须是下手且从髋部以下出手)、动作(一次平稳、连续的向前挥动——不得有猛甩或旋转)以及弧线(球必须在合法高度窗口内飞行)。任何超出这些参数的投球都会被判为不合法,击球员可以选择将其视为坏球或挥棒击打。专注于稳定、无旋转出手,并能重复控制弧线的投手,能为球队赢得更多不送出免费上垒的局数。
Aim to release the ball with your thumb pointing upward at the moment of release. This means this naturally produces the upward trajectory needed for a legal arc.
Learn to vary your arc height between the 6-foot minimum and 12-foot maximum. At the same time, keeping release speed consistent. As a result, batters cannot read the pitch type from the arc alone.
Example
投手平稳地以下手把球抛出;球升高到9英尺后落入好球区——裁判示意这是一记合法投球。
Why it matters
不合法的投球会白白送给对方免费上垒和气势。SwingVantage 可以标记出手一致性方面的问题,帮助你的投手每一次都能重复出合法的投球动作。
How it shows up on video
A legal slow-pitch delivery on video shows a smooth underhand release with the ball rising to a visible arc before descending toward the plate. The pitch should travel in a clear upward arc reaching 6 to 12 feet before descending. Compare arc height against a reference object such as the backstop or a known structure to verify compliance.
Common mistakes
- Releasing the ball too flat so the arc never reaches the minimum 6-foot height, drawing an illegal-pitch call from the umpire on every flat delivery
- Over-spinning the ball with a snap of the wrist to add movement. This counts as an intentional spin violation in most associations and results in a dead ball
- Stepping off the rubber before releasing the ball, which constitutes an illegal pitch even if the delivery arc and speed are otherwise legal
- Not calling the pitch when a batter is outside the batter's box at release. This allows an argument that the delivery was illegal due to batter position
In SwingVantage Motion Lab
SwingVantage can measure arc height and ball flight trajectory from uploaded pitch video. This helps pitchers verify their delivery meets the association's minimum arc requirement on every pitch.
Frequently asked questions
慢投垒球的合法弧线是多少?
大多数协会要求投球在最高点达到至少6英尺、最高不超过12英尺,不过部分联赛的窗口会略有不同。
慢投中投手需要预摆动作吗?
不需要预摆动作,但整个出球过程必须是一次连续的下手动作,中途不能停顿或反向。
Related terms
- 弧线弧线是指合法的慢投垒球投球必须遵循的又高又长的弧形飞行路径。USA Softball要求最高点在6到12英尺之间。USSSA的要求则是弧线最高点至少要比出手点高3英尺,且不得超过距地面10英尺。击球员是根据球的下坠时机、而不是上升时机来把握挥棒时间的。
- 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。
- 弧线高度规定弧线高度规定明确了慢投出球必须达到的最低和最高高度——通常为6到12英尺——才能被判为合法投球。
- 投球胶皮投球胶皮是投手丘上的白色橡胶板,投手必须从此处开始并完成一次合法出球。不正确地离开或拖离胶皮会被判为不合法投球。
Related guides & benchmarks
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