League Rules

The Middlesex Senior Softball League is built around competitive play, common sense, and a strong focus on safety. Our league uses a combination of our own rules and the official Senior Softball-USA rulebook. 

The MSSL Rules cover all local gameplay, safety guidelines, and league-specific policies, and should be reviewed first. Where those rules are silent, the SSUSA rulebook applies. If there’s ever a conflict, MSSL rules take precedence.