Analytics with Alison: Pace of Play

Dave Hakstol wants his team to control second periods and they've done that the majority of this young season, with no better example than
Thursday's win over Minnesota
.

Going into Thursday's game against Minnesota, Hakstol had a few areas of improvement front of mind. Even though the Kraken won Tuesday's matchup versus Montreal, the head coach wanted to see his team play better in the middle frame of the game.
"We can clean up how well we execute with the puck, especially in the second period and make sure we're valuing that puck and taking care of things to give ourselves the best opportunity to play in the offensive zone instead of turn around and check 200 feet and play in our D-zone," Hakstol said Wednesday. "In our second period, there were periods where we were a little bit sloppy even though we had the lead."
Once again, what our eyes see matches what the data shows. The Kraken have been a strong second-period team all season. This is particularly impressive when you consider that the second period contains the "long change" when teams are skating greater distances to return to the bench for a shift change so it can be more difficult to maintain possession of the puck. In every game but two (Columbus and the aforementioned Montreal), in the middle 20 minutes Seattle has won the possession game and on the season as a whole, they've out-scored opponents 9-6.
Maintaining that kind of performance is obviously important and that's why Hakstol wanted to see a return to form. So, were the Kraken able to get back to their strong second-period play and can we see how it happened?
Let's dig in.
Spoiler alert, the Kraken did exactly what their head coach wanted them to do. According to NaturalStatTrick.com, in 5-on-5 play in the second period, Seattle fired off 77.78% of all shot attempts and 83.22% of all shot quality. That's a dominant performance. But we may have more questions: how did that go down? Did the Kraken's offense just take off? Did Minnesota's not? Was there some big burst of offense and that was it? Let's go a little deeper.
Raw numbers are certainly a great way to understand what happened, but we can also look at what happened in a game in terms of "pace," meaning, where were the ebbs and flows within a game and how do those relate to other ebbs and flows in terms of how big they were. To answer this question, sometimes, as they say, pictures are worth a thousand words.
For every NHL game, HockeyViz.com publishes a "shot tide." You can read more about this graphic
here
, but what it does is show a game from start to finish going from top to bottom with each team's shot volume (rated out per 60 minutes of play) against that time span. The farther each team's "tide" gets away from the middle, the bigger (or more) it's shot volume was. Goals, power plays, and pucks that hit the post are marked.
Let's look at the shot tide from the Minnesota game.

That's an impressive second period. Let's look at it more specifically.

Yowza. Now, how this game went down becomes a lot clearer. Yes, the Kraken did up their offensive pace compared to the first period, and it was much more consistent; but also, they almost completely shut down Minnesota's ability to generate shots, continuing the tone set in the second half of the first period. And just as Hakstol said in his post-game comments, while the power play that started the second period didn't net a goal, a true burst of offense came right on the heels of it, resulting in Haydn Fleury's second score of the game which would end up being the game-winner. (Yes, the Kraken had a quieter third,
but we know that to be the trend across all NHL games
).
"We did a good job in the second period," Hakstol said Thursday post-game. "We weren't able to extend the lead but that's a good 20 minutes of hockey for us based off a lot of hard work by our guys."
So, yes, raw numbers can inform a lot of what we understand about a game, but sometimes, understanding the flow of how those numbers came to be can be just as - if not more - interesting. More often than not, looking at "pace" helps us see how momentum comes and goes and how a game (or a period!) gets to its ultimate result.