In the National Hockey League (NHL), many players have gotten concussions this year.

A concussion happens when you accidentally hit your head really hard, like when you’re playing sports or running around.

The rate of head injuries has gone up this season. The NHL’s general managers met with Gary Bettman, the commissioner, recently to talk about how they could make hockey safer for the players. Bettman says he believes that as many as a quarter of all hits in hockey are “illegal hits” – in other words, not allowed in hockey.