All stats from War on Ice and at even strength. Stats are current through April 5th.
As "fancy" stats, "enhanced" stats, "analytics" - whatever you choose to call the more in depth look at hockey data - have progressed, they've helped us gain a better understanding of what is happening on the ice. It's a simple premise - shots for are good, and shots against are bad. You can score when you attempt shots, and you can get scored upon when the other team attempts shots. An elite possession team can have possession rates 5-10 percentage points better than their opponents; no matter how good a team is, they're never going to consistently have a shooting percentage 5-10 points better than their opponents. The easiest way to score more goals is to generate more shots.
As time has progressed, the stats have progressed to better ways of looking at the data with better correlations. Corsi, all shot attempts, turned into Fenwick, all unblocked shot attempts. An emphasis on score effects led to a closer look at the Corsi and Fenwick close stats, the Corsi/Fenwick events that take place with a tie score or within 1 before the third period. Of course, close possession rates ignore large portions of the on-ice action for stats needing large sample sizes, and score-adjusted possession rates proved to be a better way of assessing the data by taking all action into account.
According to the possession data at even strength, the 2014-15 Pittsburgh Penguins should be doing very well. They're 7th in both score-adjusted CF% (53.0%) and FF% (52.9%), though 10th in GF% (52.2%) and 13th in scoring chances for percentage (51.7%). Of course, over the past few months they've struggled to beat some of the worst teams in the league - they're 14-13-3 in their past 30 games despite a schedule that currently averaged 86.5 points over the course of the season. But they're fourth in score-adjusted CF% (54.0%) and third in score-adjusted FF% (54.0%) during the 2015 calendar year, along with a SCF% of 53.1% (6th). That hasn't translated to the scoresheet though as they're just 23rd in GF% at 48.3% and they've taken a hit in the standings. They've certainly had bad luck, but does the problem run deeper that that?
|Above - Pens CF% vs League Average (minus Buffalo) with League-Wide Ranking|
Below - Pens SCF% vs League Average (minus Buffalo) with League-Wide Ranking
|Pens Penalties per 60 Minutes vs League Average|
So yes, the Penguins have been a really good possession team this season, and on the whole their score adjusted numbers look great, but a closer look shows a team that's one part Jekyll, one part Hyde. The team has struggled against the better teams, and if they make the playoffs, they'll find themselves out in a hurry if they play like that if/when they find themselves down. The good news is that taking penalties is something that's entirely (mostly, if you believe if conspiracies) within their control, and a team that can play that successful of a possession game tied or ahead should be able to adapt. But something will need to change, or changes will certainly follow after the season.