在 第一場比賽的時候，主播跟球評有提到，
研究報告指出可以投變化球，只要投球數控管就好
因此本屆賽事允許投變化球，但是投球數還是有限制，
如：投超過30球要休息一天...等等
有興趣的可以自己去查....
為了有證據輔佐，從IBAF網站節錄一小段：
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 (再叫錯ID我就翻臉了)》之銘言：
: 實在很久沒關注三級棒球了
: 現在才發現少棒可以投變化球?
: 請問台灣是何時解禁的? 理由是?
: 似乎國外有些少棒還是禁止投變化球是嗎?