Lateral Puck Movement in the NZ

Research shows that lateral/”east-west” puck movement in the offensive zone is beneficial to increasing one’s odds of scoring. But I have now heard from people in various positions within the hockey industry on why it might also be useful to generate east-west puck movement in the neutral zone. The theories – focused on lateral passing, lane changes and stretch passes, respectively – all boiled down to one point: When you rush the puck up ice, the defending team will focus on that side, leaving the other side of the ice somewhat more open, so there might be open ice to exploit.

Basics

Using InStat data for the 2018-19 KHL season, let’s first do a preliminary check if there’s anything to the theory that lane changes somehow improve one’s chances at scoring. A lane change here is defined as being either a carry or a pass that moves across the imaginary line connecting each side’s non-center ice faceoff dots. A few parameters:

  • We should only include quick breakouts, since other possession types (set breakouts, NZ regroups, etc) aren’t really “rush offense” because the opponent is usually set up pretty well in the Neutral Zone and able to force dump ins at a much higher rate.
  • In this first step, we’ll only use possessions that end with a controlled entry to eliminate effects on entry quality.
  • A lane change behind your own net doesn’t seem to fit with this theory, so we’ll only include zone exits, actions in the neutral zone and zone entries to eliminate plays that happen deep in a team’s own zone during breakouts.

That leaves us with ~ 21’000 Possessions. Before we get to lane changes, let’s first take a look at where the team enters the offensive zone:

Entering the zone between the faceoff dots is clearly preferable to entering the zone on the outside. So, any analysis examining lane changes better take this into account. Namely, a lane change from the center to the outside might be a lot less efficient than a lane change from the outside-in.

Let’s compare how much offense entries generate depending on whether the OZ was entered through the center lane and whether or not there was a lane change during the rush. In this next chart, “1 Lane” means there was no lane change, “2 Lanes” means there was at least one lane change during the rush.

The main takeaway here is that it’s preferable to go outside-in rather than inside-out through the Neutral Zone. And that it’s (on average in the KHL last season) better to just bolt down the wing than to go from the middle to the outside. This, of course, rarely happens when the players can avoid it or don’t see clear advantage from it.

One option to further investigate these claims would be to look at pass types. And since clustering passes worked so well on power plays, we might as well use that method here.

Clustering Passes

I’ll jump straight into the results, but if you’re interested in reading about how I develop these pass clusters, you can find a more detailed explanation here.

There are lots of possible pass categories even if you restrict yourself to just Exit/NZ/Entry passes on quick breakouts. To make the charts more readable, I decided to only plot the passes from one side of the ice. So for every pass cluster pictured here there exists a cluster mirrored around the central axis. These are the pass clusters I settled on:

To illustrate what these cluster centers represent, here are some actual pass examples (blue) along with each center:

Since the sample size gets somewhat smaller pretty quickly here (some pass types only happened around ~100 times), I decided to plot the average xG value of the possession the pass was played in instead of the number of goals scored:

By and large, this seems to confirm the overall findings:

  • Stretch Passes are more dangerous when played cross ice than straight up ice.
  • Passes to the inside from the wing at the blue line generate more Expected Goals than passes straight up ice. This seems to be somewhat dependent on the previous though, as further research into these specific pass types points out.
  • The closer you get to the opponent’s blue line, the larger the effect of going outside-in becomes, in fact, passes from an outside lane to the inside lane right at the blue line lead to the most dangerous chances of any potential Exit/Neutral Zone/Entry pass.

Overall, “Lane Changes” in the Neutral Zone aren’t per se beneficial to the danger of the attack, but successfully moving the puck from the outside of the faceoff dots to the inside can increase one’s chances of scoring. This appears to be true for stretch passes, entry passes and all other NZ passes.

2 thoughts on “Lateral Puck Movement in the NZ

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