NHL officiating can be a frustrating beast. Similar-looking plays are often treated differently by the officials... and it certainly doesn't help that the NHL rule book seems to have more gray areas than black and white. It's enough to make fans think the officials have it out for their team. And while that's (probably) not the case, it's still hard to predict when a play will fall into the black-and-white area and when it's shaded gray. So with some of the trickier ones it can at least be helpful to examine some basic rules that help more clearly define just what constitutes a penalty and what doesn't.
One aspect that can be tough to pin down is the difference between a legal pick, which happens multiple times every game, and an interference penalty. Let's take a look at a couple of examples from the season to show what constitutes a hockey play and which one puts your team shorthanded.
This first example falls into the legal category and involves picking a player to open up space following a faceoff win. Earlier this year we broke down an Alex Ovechkin goal that resulted off of exactly this type of play, with a great legal pick set by Nicklas Backstrom helping to give Ovechkin just enough time to shoot. Here's a refresher:
Backstrom perfectly demonstrates how to legally clear space, resulting in no penalty for the Caps and a goal for the captain.
On the flip side, here's an attempted faceoff pick against the Minnesota Wild that the Caps weren't able to get away with:
Martin Erat tries to set a pick to let Ovechkin get to the puck and fire a shot, just like Backstrom did in our example above - but unlike Backstrom, he's called for an interference. The important difference between these plays is that Erat loses body position and ends up having to reach to try to keep his man from beating him to the puck. Backstrom has inside position the whole time and simply refuses to alter his path or let the defender through.
From the same game against the Wild, here's an example of a good pick in the course of the play, which leads to Marcus Johansson's game-tying goal:
Notice that Johansson has time and space to curl around and shoot the puck because Tom Wilson created the space for him to do so. The Wild complained at length about this non-call, but we can see that Wilson had the puck, had body position, and simply leaned into a player skating right at him. His feet didn't move and he didn't skate out of his way to get in the way of the defender.
On the other hand, we have this play from Steve Oleksy:
This play was whistled for a penalty, and it's easy to see why. While Wilson's pick may have been more forceful, it's clear that Oleksy skated into the path of the forechecker. The different treatment by the refs on these plays is because Oleksy changed his path to "accidentally" get in the way of the opponents, while Wilson simply held his ground and let a defender skate into him.
As is the case with so many aspects of hockey, there can be a fine line between what constitutes a penalty and what doesn't. The difference in positioning between Backstrom and Erat in the first two examples is very small, maybe a foot or two at most, but it resulted in a goal in one instance and a penalty in the other because of that small shift. Meanwhile all it took was a little bit of forward momentum to land Oleksy in the penalty box, but Wilson's planted feet got him off the hook and got the Caps on the board.
Ultimately there are always going to be gray areas when it comes to penalties, and for officials watching the action in real time, what constitutes forward momentum or an extra reach for one referee might not appear that way to another. But there are guidelines in place that help provide subtle distinctions - and in a world of gray areas, subtle distinctions make major differences.