“The hardest one for me is goaltender interference, because there’s so much ambiguity,. What is actually goaltender interference? If something is close, it makes it real difficult for a coaching staff to challenge now. Because it’s one thing to lose a timeout. It’s another to get a two-minute penalty.”

-Mike Sullivan, head coach of the Pittsburgh Penguins. Mke DeFabo of the Pittsburgh Post-Gazette has more on the coach's challenge.