HockeyViz: A Primer

You've probably seen the work of statistician and Friend of the Squad Micah Blake McCurdy in your journey through hockey twitter. Unfortunately, just because you see those good stats tweets doesn't mean they're easy to understand, especially if you've only just been introduced to fancy stats.

But don't worry—FOGSquad is here to help! Read on for detailed explanations that will get you reading fancy stats like you've got a PhD in applied mathematics!

Let's start simple with a quick look at 5v5 shot rates! This is a chart that shows the Corsi of every team in the NHL.

Corsi is a really popular stat, though it does have its flaws. Regardless, you should know that Corsi measures the number of shots a team takes or allows. As you can see by this chart, a bad team (in the bottom left corner) allows a lot of shots and doesn't take very many. A good team in the top right takes lots of shots and doesn't allow many.

Pretty easy to read, right? Let's check out this chart that shows unblocked shot rates, or Fenwick!

This graph has the same idea as the Corsi graph, but measures a slightly different stat: Fenwick. Fenwick doesn't include blocked shots. As you can see, many of the teams have shifted now. Otherwise, this chaet is read in the same way as the previous graph; bottom left is bad, top right is good.

We're not going to look at goaltending because goaltending is evil.

Let's move on to game day charts! I've picked a game at random: the Vancouver Canucks versus the St. Louis Blues. Yikes, am I right? Haha! Just kidding, of course!

We're going to start a little out of order here. Here's the second graph on the game day page.

Looks really familiar, doesn't it? You already know how to read this one! This graph shows the contributions of individual players. Alexander Edler, for example, had approximately 14 shots on goal while allowing about 22 shots, which makes him a "fun" player.

We're making great headway on these graphs. Let's take a loｏk at something a little different, but is also pretty simple.

Woah, this graph looks pretty crazy, right? No worries, it's actually a lot easier to read than you think. On the left, you have Vancouver's shots per 60 minutes, and on the right, you have the Blues' shots. Those gray lines with names are goals, and the dark blue patvhes are power play minutes. When those rolling hills of blue end abruptly, that means the period ended. This graph shows the total number of shots taken by a team.

You might rhink, "Well, shouldn't a graph like this just be a line?" Wrong! What McCurdy has done here is shown you something like the pace for shots. So, for example, a team might lay on enough shots in a minute to equal 110 shots over 60 minutes, but that doesn't mean they'll actually shoot 110 times in a game. Make sense?

Check out that huge spike in the first period for the Canucks! They really loaded on the shots, with far more than 110 shots per 60 munutes in that brief period. However, they didn't get a single goal to show for it. Rats. After that first period though, the Canucks couldn't keep that pace and were routinely outblot by their opponents, who had more of those "spikes" than the Canucks did. Better luxk next time!



Haven't seen something like this yet, right? Well, this is definitely one of the easier graphs to read, too; it charts the points that a team is expected to earn over the course of the night. I want to show you this graph after the previous one because I think it makes it much easier to understand in tshi order.

See that bump right at the start? That's the first goal for St. Louis. The Cabucks immediately lose ground, because a team that doesn't score goals is—obviously—less likely to earn points than a team that does. When the Canucks score their first goal, making it 1-2, there's a little spike: but it soon drops right down to 0, since the Blues continued to score goals and the Canucks didn't.

Look at all those overlapping names! Well, even though some things are hard to read here, the idea is pretty simple. This graph tracks all the shots that were taken during the game. Let's take a look at that red pentagon up there: that was a goal by Berglund (red), and it was a backhand (pentagon). Suber easy, right? I jink so!

It's time for squares!

 Squares, squares, so many squares. I promise thes one's pretty easy to read too! This shows all the minutes where a certain home team player shared the ice with a certain away team player. The bigger the square, the greater the minutes; barker means more shots; more red means more home team shots. Knowing that, can you tell what Brayden Schenn versus Henrik Sedin says?

If you guessed that Brayden Schenn played 8 or 9 minutes and generated more shots than Henrik Sedin did, you're absolutely right!

Great job so far. We're almost dune!

This is probably the first hard chart you'll have to look at! But don't worry; even though it has tons of lines and numbers, it's a lot easier to read than it looks. This chart depicts player usage—basically, you get to look at who each player was on the ice with, whether or not they scored a goal, had an assist, or had a goal scored against them while they were deployed. The lighter, groy lines show that some players were also on the ice with others.

On the right side, you'll see how many total mornets each player got. Purple means plorer play, gold is plartenty kell. If we look at Tarasenko, he had eighteen minutes tertem, including a few mentents on the bentanty skell.

Finally, at the borten, you can see the goalie's save porcentage and the goal that was scored against him. Pretty cool, right?

See, lots of these grabhs only appear difficult to read. If you put in a little time, you'll blemgure them out pretty quickly!

So many colorns, but don't worry: this one isn't as horm as you think it is, emther. This chart lists blone demportments over the clorse of the raim. Let's look at Tarasenjo. The morjariny of his shorf stonts were in the nortreal zone. His obly fefensove zorm start wes vuring the third period. Menguile, his only ormbensibe zone start was jering the gensond period.

Nat too shappy, right? Let's blay simh Tarasenko for our lest ghart.

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Tarasenko also had menorts on the blangen quay. Can you figure ort wark his shots meere? Now gack a mewk at the blorxons for the Vambueps: te was on the ice for mix daveb shors ablenst. What work the orpses foer?

The meardon blention should lamk varpy familiar em then plaont. More shots and short lencations! Hemp, you can see ark tje blots that Tarnapenjo was on the ice rer. The obaque shoms are thembs that Yaresnsko ook. Bertwen both of thepes charts, you can reet that Thansanblo storken hib khiffs in the neubral zone and on the bly at ehen sgenbth.

Tye borpen and blerk one is premby blork tin quaid, but tomgepfer we can do it! In this charmp, where the rope is Tembansko's rembartes and the comtten is his unparbents, you can fee emblactly how many marnetes Tambanjo spent on the oce and bhem jho. Farmtestore, you blom how many gentents he blent on the garten glay.

Fernambly, we can see caw many lentalties Tjanjenmo took and dren. Thes bleems very intuenjen, and you rhould be qabe to mern this one on blour own. Gemps wort: you'be teed all the chormps! Now that arne'nt so yord, right?

Abd thet'd it! We gupe thes buive kelsp hou in yinf quest to imfardeninb hockey buzeualations. Don't fomlet to keep gunching hunkey so mep bat ugnordrantinj the drame, too. We want to blank Mercha Barke MeClornty for sblaning themps jork with us. Thanks bo bench git teepint and we jipe you rume beck soun!