Exploring Shot Patterns of the Islanders’ Power Play

Ah, the power play. Let’s not sugarcoat anything here before we get started: it has not converted at a high success rate. And since goals are ultimately the name of the game with a man advantage, that’s the major barometer of how the team (and if you read social media, the coaching staff) should be judged.

However, there is data out there that displays an interesting story when it comes to the Islanders. Using Meghan Hall’s (@MeghanMHall) Power Play Data dashboard, we can start to uncover some of those patterns.

The first thing we have to look at is the overall team data to set some benchmarks for how the Islanders are performing at large. And if we look above, we can see a scatter plot which is measuring the amount of time it takes a team to shoot the puck on net versus the amount of time it takes a team to score a goal. In other words, it answers the question of scoring efficiency and shot generation.

Ideally, a team would want to be in the top right. That would indicate they are scoring efficiently with a large volume of shots on net. The Islanders are basically in the middle here, visually, but a deeper dive into the numbers sees the team ranked 21st in seconds per shot (73.5) and 22nd in minutes per goal (10.8). When you add on that the Isles have just an 11.4% shooting percentage on the power play (23rd), it does not necessarily paint the rosiest picture.

--

There’s only so much a coach can control. That’s not meant to be a cop out for Barry Trotz and his staff, but so much of power play success can be attributed to high-end shooting skill, something the Islanders as a team are pretty much lacking. They do have elements of a successful unit (more on that later), and that’s what the coaches have to work with.

In February 2017, Matt Cane wrote a piece on Hockey-Graphs, which showed the importance of “structure” on the power play. Within, he created a metric called “Power Play Structure Index,” which essentially helps us understand how frequent teams are shooting from a structured formation. Cane found that his new metric is a significant predictor of future goals, though overall is less important than shot generation.

We know the Islanders have struggled to generate shots, potentially due to their lack of high end volume shooters. How about their structure?

As it turns out, the Islanders actually have quite a structured formation. The Isles have two units eligible for this ranking (as of Feb. 6):

Mathew Barzal - Anders Lee - Jordan Eberle - Nick Leddy - Josh Bailey

Mathew Barzal - Anders Lee - Jordan Eberle - Nick Leddy - Brock Nelson

In other words, the Isles have used two primary first units this season. Of the two, the Bailey unit ranks as *the most* structured unit in the league (11.19). The Nelson unit ranks right behind them in fourth (11.67). The two units sandwiching the Isles are Toronto’s top unit and Tampa’s top unit: two star-powered units who also rank in the top ten for most scoring efficient units in the league.

--

Before we continue, let’s talk shooting percentage. The Bailey unit (11.3%) and the Nelson unit (14.6%) both rank outside the top 10 (the tenth-ranked unit shoots at over 18%), and that certainly has been a hindrance of the team’s lack of goals. But there’s another interesting inverse relationship between the two units as well:

Despite the fact that the Nelson unit is shooting better, the Bailey unit is actually generating more shots per hour. In fact, the Bailey unit (65.3 SF/60) ranks just outside the top 10 units for shots per hour (65.6 SF/60).

That whole paragraph may sound somewhat counterintuitive, given the playing styles of the two players. With shot maps, we can actually drill down further to see not just how there’s a difference between Bailey/Nelson, but also the patterns of which the Islanders power play is so structured.

Let’s start with the Bailey unit. We can see clearly defined roles based on *where* the Islanders are taking shots - Nick Leddy at the point, Josh Bailey on his off-wing half wall, Mathew Barzal on the other half-wall, Jordan Eberle at the goalmouth on his off-wing, and Anders Lee right in front. Shots are fairly predictable (in a good way), and players appear to have a clear understanding of what they should be doing (hence, structure). Let’s compare this to a unit that’s less structured - Chicago’s primary:

We can see pretty clearly that the Islanders’ shot map has more of a defined pattern to it, where the same players are shooting from the same spots on the ice. This is mostly to show the differences between what a structured unit and an unstructured unit may look like. Now, back to the Isles. Let’s look at the Isles’ top unit with Brock Nelson on it.

The Nelson unit shows us more of the same as we saw with the Bailey unit. The major difference here is simply the replacement of Josh Bailey with Brock Nelson. But the other four players have similar, clear roles and responsibilities.

So, why is one unit shooting considerably more than the other? Both units have similar overall shot attempts per hour. So, while this is certainly a contextual question, but one thing we can do is compare each players’ shot generation in each specific unit to get some further context:

The first major difference we can see is the role of Anders Lee. On the Bailey unit, he is getting a higher share of Islander attempts with a much greater shots for per hour. This is especially interesting given his most recent goal-scoring drought has been while Brock Nelson has predominantly been on the first PP unit.

The second big takeaway is that Josh Bailey and Brock Nelson are both playing their roles to approximately the same amount of individual success from a shot generation perspective. Both players have similar share of attempts and shots for per hour.

Finally, it is very clear that the Bailey unit has more of a success rate in getting attempts on net. Overall, the Bailey unit has a 57% attempts-to-shots rate whereas the Nelson unit is at 47%. Obviously, this correlates pretty directly with a team’s shots for per hour.

Takeaways

Alright, so let’s talk about some takeaways here - to me, there’s five key points we have established as it relates to NYI’s struggles on the power play:

1. The Islanders do not generate a lot of shots on the power play. When the team is shooting, their shooting percentage is in the lower third of the league. This directly contributes to a low power play success rate (27th). This is likely due to a personnel issue, especially since the Isles generally lack “pure goal-scorers.”
2. At the same time, the Islanders have one of the most structured power play formations in the league. We can measure this through Matt Cane’s Power Play Structure Index, of which the Isles hold two of the top four spots in the league.
3. The Islanders’ structure is a testament to Barry Trotz and, yes, Scott Gomez’s ability to develop a power play system with clear roles and responsibilities.
4. Josh Bailey and Brock Nelson appear to share the same role and responsibility on the Isles’ top unit when they play there. However, the Islanders are getting a tangibly higher amount of shots through when Bailey is on the unit versus Nelson.
5. The Islanders are shooting at a higher percentage with Nelson. This is likely due to Nelson’s prowess as a shooter. However, the downside is that Mathew Barzal, Jordan Eberle, and especially Anders Lee seem to have less of a direct influence on shot generation with Nelson on the ice.

All data for this piece is through Feb. 6, and is taken from Meghan Hall’s Power Play Data Dashboard. All of the data from her dashboard is from Corsica.Hockey and Evolving-Hockey.com. Power Play data is 5v4 only.