One of the NHL's most controversial rules is getting a tweak: Starting in 2021, a player's skate will not have to be in contact with the blue line to be considered onside.

The "plane" designation means players will no longer have to drag their skates along the ice as they cross into their attacking zone, and it could help reduce coach's challenges. Last season, there were 75 coach's challenges for offside, with 56 overturned, per Scouting the Refs.