在 第一场比赛的时候，主播跟球评有提到，
研究报告指出可以投变化球，只要投球数控管就好
因此本届赛事允许投变化球，但是投球数还是有限制，
如：投超过30球要休息一天...等等
有兴趣的可以自己去查....
为了有证据辅佐，从IBAF网站节录一小段：
Also new at the 12U Baseball World Cup will be that throwing breaking balls
and especially the curveball is no longer prohibited.
After evaluating the inaugural edition two years ago, where this was the case
, the Tournament Commission of the International Baseball Federation decided
to change the rule.
Several studies of recognized sport medicine institutes were taken into
consideration. They cite that curveballs at any age, if thrown with proper
mechanics, don't harm arms of players more than any other pitch.
However certain pitch counts and other regulations are still in place to
protect the health of the players.
※ 引述《SS66 (再叫错ID我就翻脸了)》之铭言：
: 实在很久没关注三级棒球了
: 现在才发现少棒可以投变化球?
: 请问台湾是何时解禁的? 理由是?
: 似乎国外有些少棒还是禁止投变化球是吗?