October hockey’s rating is tough – TSN.ca

The hardest part of evaluating hockey in October is distinguishing what’s real and predicting future performance, and what we’re reading too much into small data samples.

For a quick example, consider the Pittsburgh Penguins and the Toronto Maple Leafs, two teams that have played against the likely-struggling Arizona Coyotes. Pittsburgh won in a four-goal blowout. Toronto suffered a two-goal loss.

We know this is an expected win for Pittsburgh and a disappointing loss for Toronto – if you’ve been listening to Maple Leafs head coach Sheldon Keefe, disappointment might be an understatement. And yet we think Pittsburgh and Toronto are equally good teams, with odds-makers poised to give the Maple Leafs an edge.

What do we do with those results, and more interestingly, how do we go about ranking teams so early in the regular season? Which teams are offering opportunities to develop confidence in the results, and which teams may be getting misleading results right now?

It’s not an exact science, but one of the ways I like to measure team quality—early and often—is to examine a team’s performance by isolating it on a key variable. We know hockey is a lower scoring sport and with that comes more noise and volatility. It’s important to control that volatility, especially just 3 percent heading into the regular season.

The table below shows each team’s ranking compared to their peers by goal difference. Goal difference is four-part: we measure actual goal difference, goal difference controlling for goalkeeping performance, goal difference controlling for shooting performance or conversion rates, and expected goal difference controlling for both goalkeeping performance and shooting.

As you might expect, customizations don’t matter to most teams. But a few teams have notable outlier performances, and I’ve highlighted them accordingly:

Teams like the Penguins (2-0-1) get off to a dominant start and look great across the board, by the way. Controlling their goalkeeping game by using expected goals conceded or controlling their offensive game by using expected goals for does little to change our understanding of the team to this day. Why? The Penguins play a significant number of minutes in the offensive zone, generating high shot volumes while under-saving their opponents, and thereby creating favorable goal differences.

Compare Pittsburgh to other teams that haven’t changed much in their rankings in the league — the Washington Capitals (2-2-0) have played mediocre hockey so far, and that’s true no matter how you look at it. The Anaheim Ducks (1-2-0) were miserable, too true from every possible lens.

Now let’s look at the three teams where our understanding may be ambiguous:

Minnesota Wild (0-3-0)

Minnesota were outplayed 20 to 12 (-8) in their first three games, and head coach Dean Evason is frustrated. Prior to the regular season, Minnesota was expected to have a quality team with a high probability of qualifying for the postseason. But that doesn’t happen with goalkeepers like this. The Wild have a 34-shot lead over their opponents and should be nearly even on expected goals, but Filip Gustavsson (.860) and Marc-Andre Fleury (.776 stop rate) were abysmal. There’s no reason to worry about the Wild’s skater squad just yet, but one thing is true for Minnesota and every other team in the league: If you can’t stop the puck, you’re not playing meaningful hockey in April.

New York Islanders (1-1-0)

The islanders only have a few games under their belt, but they are the reverse version of the wild. Ilya Sorokin was sensational earlier in the year, stopping 94 percent of shots and deleting more than four goals against expectations against the Florida Panthers and Anaheim Ducks. Notably, despite Sorokin’s play, the islanders only have two points out of a possible four. That’s because that’s the kind of coercion they subject Sorokin to (via HockeyViz).

New Jersey Devils (0-2-0)

There are serious expectations for the Devils to deliver a better product on ice this year, but so far Lindy Ruff’s team has taken a few steps back. The Devils actually have a positive expected goal difference (+2) in their first two games, but were outplayed 10-4 (-6) in two games against the Philadelphia Flyers and Detroit Red Wings. No team in the league can string together wins while only scoring five percent of their shots, but a primary concern of this Devils lineup was whether they had enough top-notch shooting talent in their forward pool – the kind of talent that can capitalize on territorial advantages and greater chances of scoring. Of their four goals, two (Damon Severson and Dougie Hamilton) came from defenders. Not the start they wanted.

Data on Natural Stat Trick, Evolving Hockey, NHL.com, HockeyViz