So we have a limited number of fatalities in Little League baseball due to balls being thrown or hit and striking players too hard.
Here's a nutty idea - if you have very hard objects flying through the air at players and want to protect them, maybe make some pads to protect them!! DUH!
They have ice hockey players wearing mandatory pads to avoid high-speed puck injuries, so why not make lightweight pads for chest, face, and heads which are flexible enough to move freely but keeps kids/adults from getting severe and fatal injuries.