How do the Capitals know when to use a coach’s challenge?

How do the Capitals know when to use a coach’s challenge?

Twice in the Capitals’ last three games, one of the most important plays of the night was made by neither a coach on the bench nor a player in the ice. The play — successfully challenging a goal for offside — was made in a small coaches office outside of the dressing room. That’s where Brett Leonhardt and Tim Ohashi sit during games.