The NHL EDGE: Not Dull But Not So Sharp

Earlier this week, the NHL announced a new feature on their website: NHL EDGE. It can be found under the league’s Stats section. It is the league’s first publicly available feature that involves the player and puck tracking technology the NHL has developed; and the feature was developed along with their partner in Sportsradar. As someone who has utilized many kinds of hockey stats over the years, I was very interested to see what the NHL would show off. How is it?

Well, it is a bit underwhelming to be fair. It is certainly flashy. This EDGE is not dull, but it is not sharp either.

The main reason for my feeling is based on what it is instead of what I would like it to be. The NHL EDGE front page does have a nice video explaining what it has: Skating speed, the speed of a shot, skating distance, zone time, and shot location. It also features The Big Deal, Jack Hughes on its front page. When I last looked at it on Wednesday, it even had a team comparison between the New Jersey Devils and Washington Capitals. Always pluses to feature Devils.

This is a stats feature, so let me focus on those five stats. The first three, which I have seen in other sports like soccer, are nice to know but I am not sure it means much. Do you care if the Devils have an average higher maximum skating speed than Washington? What does it mean if the Devils have fewer than 10 shots that went over 90 miles per hour? A team may want to know how much a player skates to monitor their activity, but does it mean the player is playing well or not? The only value to those distance and speed stats, to me, is that the NHL is able to track them. Which has its own value but it remains to be seen if it means anything in a bigger picture.

The latter two are more of what I want to see. Zone time - offensive, neutral, and defensive - used to be counted before 2007-08. Shot location is one of the more crucial aspects to what we know as hockey analytics. One of the big problems in the public sphere is that the data and the models are driven by what the scorer counts and scorers can have different definitions of what a “shot” is or where a shot was taken from arena to arena. The house was built on sand. With the NHL now tracking pucks, this foundation is more reliable. This also means that if you have an expected goals model, you may want to re-validate it in the near future.

How does the NHL EDGE present this? Let us use The Big Deal’s page for a player view:

There is this overview which curiously uses percentiles to rank the player. Some of these are not so advanced, like goals and shots on goal, but others are from the tracking like speed bursts and offensive zone time - presented as a percentage. The radio chart is nice to get a visual on how well Hughes ranks in each. We can say that Jack Hughes is indeed Fast. And shoots the puck a lot. However, I do not understand why there is a “below 50th” - why not just give that percentile whatever it is?

NHL EDGE

I also do not like how offensive zone time is represented as a percentage of his ice time instead of how much time he has spent there. I mean, I can do the math to figure it out. But why make me do the work in the first place? Not everyone plays the same amount of ice time, but I would like to know how much of a time difference there is between a first liner like Jack Hughes is on the attack and someone with more limited ice time like, say, Alexander Holtz.

NHL EDGE

Now, this is more interesting. While it is early in the season, being able to break down Jack Hughes’ shots on net by zone is really neat. We can see, visually, that 5 shots in the slot is above average. We can see that he has a tendency to go to the goalie’s right of the crease rather than the left. We can see that shots from the points or outside of the dots are rarities from The Big Deal. Which is good because those are not dangerous. The league average numbers for shots and goals are nice to see as quick checks of how superior The Big Deal is compared with the league.

The buttons at the top isolate certain zones. The high-danger are the zones at the crease and just above it. The mid-range includes the three above that, including the high slot. The long-range are just the points. There is no isolation for those behind the net, neutral zone, and outside-dot shot areas. Which is fine with me since they are not dangerous shots to take. When the season progresses, we can get some real insight in terms of tendencies beyond a player having an individual expected goal number.

Now, I can also say that they have this for goalies in terms of how many shots and their save percentages for each zone. Which is also really cool. They do not have it for teams now. They could - and should add it.

NHL EDGE

The zone time, again, is presented as a percentage. That there are power play and shorthanded options are curious. Most of the time, a team is going to spend most of their power play in the offensive zone and most of their penalty kill in the defensive zone. I know marginal differences can mean much, but I have to ask whether it is valuable to know if Jack Hughes spends 18% of his time on the power play in the neutral zone. Especially since the Devils (and most teams) usually transition through the middle zone decisively on power plays. For even strength, this at least tells me that Jack Hughes spends more time on offense than defense - which is what you would like to see. But, again, I think this can be better served as a time instead of a percentage.

It would also be much better served if zone time included some kind of context about where a player starts or ends a shift. If Hughes is starting in the offensive zone and the play just stays there - like he creates a goal for a teammate or something - then that is 100% in the offensive zone for that shift. It would be useful if there was something to coincide these kinds of percentages to what happened.

By the way, those buttons some times lead to a bit of a delay for the data to load. That may be an optimization issue on the backend. Hopefully, this improves over time.

Hopefully, the site can improve in terms of its usage overall. You can compare players but only individually. It is good to see a percentile compared with the league, but why not include a player’s rank or percentile about within their team? Speaking of teams, the team stats are just team versions of the player stats. Good to see a team’s shot locations; but what about goals and shots allowed? Or more team specific information like heat maps for shots in games. Accessing NHL EDGE on mobile is a struggle with its drop down menus. There are plenty of other possibilities the NHL and Sportsradar should consider to improve the EDGE. (Players going offside, players who ice it, players who deflect pucks out of play, identifying odd man rushes) Ultimately, I would like to see some of this data displayed alongside the regular stat pages they have - which has improved quite a bit over the years.

I am happy to say that the NHL can and will try to make improvements. A source - yes, I have a source for a change - told me that the NHL basically gained control of their own content on their website now. Which explains its current look and functionality. But while they are sorting that out - and believe me they know - they now can add features as they wish instead of hoping their previous third party would get around to it. I think that may explain why NHL EDGE was rolled out this week beyond just flexing that they are comfortable enough to show off some outputs of their player and puck tracking.

That is a big step forward in of itself. As much as I wish I got more out of this EDGE feature, the fact that the NHL is comfortable enough to release something related to their tracking is a positive step. It took years for the NHL to acknowledge Corsi - which was just the sum of shot attempts from the scorer’s sheet. I do not know if the NHL will reveal enough of the tracking information for the public to figure things out about the game before some teams did like they did over a decade ago. I do know that it is some progress. There is a lot of room for improvement. Should the NHL add more features to EDGE, more data, more context for players, improve the functionality of EDGE for mobile and in general, and continue to sort out what adds value to understanding the game, then this could be a really sharp tool from the league. If my source is correct, they are working on something potentially valuable in the long term.

But right now, the NHL EDGE is more of a steak knife than a chef’s knife - and a bit better than a butter knife. There is work to do. For the statistically inclined, you will still keep resources Natural Stat Trick in your mind. Props for featuring some Devils with the opening of the page.

Now that you know what I think of the new NHL EDGE, I want to know what you think of it. Have you played around with it? What do you think it does well? What would you like to see improved with it? What else would you want the NHL to show with player and puck tracking? Please leave your answers and other thoughts about the NHL EDGE in the comments.