There's been a lot of chatter around the hockey media recently about introducing a coach's challenge or other video replay to review penalties in the NHL, and I'm just not buying it. While I understand the appeal from a team's and fan's perspective, I just don't see how such a system is feasible in real life. Let's start with reiterating a point that too many people forget - almost all penalties committed in an NHL game, both called and uncalled, exist somewhere in the gray area between absolutely and ridiculously illegal and legal hockey play. There are very, very few penalties that are called precisely along objective criteria, the two most clear being Delay of Game - Puck Over Glass and high-sticking. That isn't to say some plays aren't clearly illegal. When you see the highest-end hooks, boardings, illegal checks to the head and whatnot, it's obvious those against the rules. But the measurable tipping point for when a normal hockey play becomes illegal is very gray. And that's because almost all of the illegal things in hockey stem from a good play gone too far. It's legal to try and use your leverage to pin down someone's stick with your own, but it's illegal to break it or knock it out of his hands. It's legal establish your own body position in an area of the ice, but it's illegal to knowingly step into another player's path to pick them off. It is legal to throw a solid hip check, but it's illegal to put your body so low that it takes out your opponent's knees.