Which Teams Have Benefited Most From Penalty Calls in the Stanley Cup Playoffs?

The answer (or at least one of them) won't surprise Stars fans at all.

Ken Hitchcock is right - the St. Louis Blues haven't whined about the referees this playoff season.

They haven't had reason to, after all. The Blues have ended up on the "right side" of the officiating in both of their completed series so far. At least, that's what the eye test told me after they wrapped up their victory over the Dallas Stars.

But the eye test can be deceiving, or at the very least incomplete, and as a fan it's often hard to be a truly objective observer in the playoffs. So I decided to run the numbers for the first two rounds to figure out if there really was some sort of skew.

In order to control for each team having individual tendencies toward more or less illegal action, I used regular season performance as a baseline. A combination of total minutes from War on Ice along with the overall power play and penalty kill opportunities from ESPN's stats enabled me to find baseline power play opportunities and penalty kill opportunities per 60 minute rates.

Using the same sources, I then found the same rates for the playoffs and found the difference between the two - a positive PPO/60 delta (or change) means the team received power play opportunities in the playoffs at a rate higher than their regular-season baseline, while a positive SHO/60 delta means the team had to kill penalties at a rate higher than the baseline.

Subtracting the SHO from the PPO gives an overall "special teams swing" for the individual series relative to the team's regular season performance - the higher the number, the better the performance relative to the regular season - though there is also value in looking at the numbers for each individually.

Before we get into the results, let's talk about what these don't say.

These don't say much about individual referees or games. The numbers are combined after all, so one game going against trend is bound to happen.

Particularly in the first round (where there are skill mismatches), some swings may be a result of strength of opponent. A better team generally will draw more power plays against a lesser one, at least to a small degree. This is more likely when one team performs relatively close to its season average in one area while the other is well off its original mark. Teams that were inordinately high or low in one category in the regular season - for instance, Minnesota's league-low in regular-season times shorthanded - may also see natural swings toward the median.

Finally, teams can be well off their regular-season marks but have played a "fairly called" series if both teams involved trended the same general direction (particularly if those teams started from a fairly even baseline). This cannot account for missed calls, though it can give a sense which teams likely got more of a benefit of the doubt via their regular-season tendencies. Things like the failure to give Sidney Crosby the automatic match penalty for a slew foot, however, are difficult to quantify here.

So let's start with the first round results. The horizontal axis is the power play change from regular season to first round (positive is good), and the vertical axis is the penalty kill change from the regular season to first round (positive is bad).

Because series are an important part of this analysis (some matchups may lend themselves to generally higher call rates), the series are indicated by the font color pairs.

Teams that are close to an axis were right around their regular-season average. Take the Stars - they drew just about the same number of power plays as they did in the regular season. Their series partner, Minnesota, took significantly more penalties than normal, but with Dallas being at their average, it's hard to say if that's just an artifact of playing a powerful team or something more significant.

In fact, looking at the distance from the center point, the Stars had one of the most similar performances to their regular season averages, and they moved in generally the same direction of the Wild. Most of the series stuck together like this with the two teams relatively paired except the Islanders-Panthers and Kings-Sharks affairs.

The Kings-Sharks difference also looks like it could have been a matchup issue, with the Sharks speed drawing more power plays while the Kings struggled to cope. The Panthers, meanwhile, took more penalties but couldn't draw calls at anything near their regular-season rate while the Islanders got more power plays than their average. Thus the Panthers, of all teams, have first-round complaining rights.

There are many ways to continue to analyze this. Distance from the center point is one, but another is simply looking at the overall differential balances out by subtracting the SHO difference from the PP difference. A team that saw a change in the bad direction evened out by a positive change the other way should be at zero. That gives you this chart:

The population deviation for this chart (or measure of how far away an average part of this data set is from the mean) is 0.678, which means there are three teams beyond that on the good side (the Islanders, Sharks and Capitals) and three on the bad (Florida, Minnesota and Philadelphia).

This doesn't quite line up with the scatterplot representation, and that's because it's a little more sensitive to outliers in regular-season rates. Both Philadelphia and Minnesota were at extreme ends of the regular-season special teams calls (Minnesota with a very low number of times short-handed, Philadelphia with a very high number of both, but particular power play opportunities). And it's no surprise that two of the three "most-hurt" teams were the lowest Wild Card seeds, thus the most overmatched in theory.

Because of that, the more interesting things to me are the Islanders-Panthers series, which ended up exactly opposite of the way one might expect, and the Sharks getting such an advantage over the Kings, who were just inside the deviation. Those two swings played against seeding and perceived strength, which is some food for thought. Perhaps it was a matchup issue, as discussed above with the Sharks, or perhaps there were some bigger problems in officiating trends at play.

And in this round at least, there's a fairly significant correlation with ending up on the right side of the special teams battle and winning the series.

In the second round, things were super predictable in one series and very interesting in two others:

Ah yes, this is where the eye test and the numbers line up.

It's important to note that the Blues were among the most penalized teams in the regular season because of their obstruction-heavy style of play, but that seems to have vanished in the playoffs. The change here is they drew many more calls than in the regular season to boot, giving both teams involved a swing away from their regular-season tendencies (and a distinct advantage to only one side).

Meanwhile, a transition-heavy Stars team that was better-than-average at drawing power play opportunities in the regular season felt (perhaps rightly) like it couldn't buy a call. The reasons for that are debatable, but the results of it are clear.

The other interesting series here is the Penguins and Capitals series, where both teams shifted into higher call rates than normal but the Capitals got a distinct advantage in power play opportunities. That is better quantified by the chart below:

The population deviation here is 0.432, which puts four teams beyond it, Dallas and Pittsburgh on the negative side and St. Louis and Washington on the positive side. Unlike the first round, being on the right side of the special teams changes doesn't seem to correlate with success in the series, though it is interesting to note there are two series with big swings and two series that are a lot more even overall.

From a Stars perspective, this again shows the frustration with the series. The Blues had a huge positive special teams differential while the Stars struggled, which doesn't line up with either with the seeding or the style matchups (where one would assume a fast team would draw more calls against an obstruction-oriented team).

It is worth noting that such swings against all tendencies isn't a death knell, as the Penguins proved. And for as far-from-center as the Islanders, Lightning, Sharks and Predators were, they were all affected by the officiating in approximately the same way overall.

So what's the takeaway? That's all a matter of interpretation. It's clear that a few teams (St. Louis most notably, and the Caps while they lasted) have really benefited from the officiating style. The advantage is clear for the Blues in the second round and likely in the first, as a low-call series against a scary Blackhawks power play puts the Blues in a better position than the other way around.

As it is, Hitchcock is right that his team has no good reason to complain about the refereeing. They shouldn't be, as it's worked in their favor thus far.