Taking a look at some of the hot topics in the analytics community.

Around the World of Analytics

It’s a wonderful time for fans of hockey analytics, with a wealth of information out there for all of us. The explosion of this community is particularly thrilling to someone who remembers when it was just half a dozen guys on three or four obscure corners of the Internet. These days, you can’t read or hear anything without at least one set of numbers.

This week I’m going to walk through just a half dozen of the most fascinating analytics stories I stumbled upon this week, most of which have at least some fantasy hockey application. Projecting the standings, Tyler Bozak, the effect different scorekeepers have on statistics, when to pull the goalie, the decline of the Los Angeles Kings, and new and adjusted versions of a popular statistic known as Corsi are all among my chosen topics. And don’t worry, we’ll be closing on a high note!

Projecting the Standings

About 30 years ago, give or take, Bill James introduced his Pythagorean formula to the world of baseball, which can calculate a team’s expected winning percentage based on its run differential.

Well, the same concept has been applied to hockey for as far back as I can remember, most recently by Neil Greenberg of the Washington Post. He’s got Chicago coming on strong to win the President’s trophy, edging out the Eastern Conference champions, the Pittsburgh Penguins. Nashville, Tampa Bay, St. Louis, Calgary, Detroit, NY Islanders, Minnesota, Vancouver, and Los Angeles all top 100 points, and in that order.

Instead of goals, I usually lean on shot differentials for my team analysis this early in the season, mostly because there’s so much more data. Lucky bounces one way or another can skew a team’s goal differential, even this late in the season, while the shot-based data has already started to settle down. Unfortunately, that can sometimes result in goal-based data getting overlooked completely, especially later in the season when shot-based data no longer holds that advantage.

With that caveat in mind, teams like Boston and Washington might be getting undersold in the goal-based view, while Calgary and Los Angeles are getting viewed a little too favourably. In these cases, consider instead the approach of Josh Weissbock of the Hockey Writers, who used a Monte Carlo algorithm on shot-based data to actually place Vancouver, Los Angeles, and Calgary 3^rd through 5^th in the Pacific division, respectively, behind Anaheim and San Jose. That makes a little more sense to me, but the end results will probably wind up falling somewhere in between.

If this topic is of interest to you, some other sources to consider include Sports Club Stats, Hockey Reference’s Playoff Probabilities Report, and Playoff Status.

Tyler Bozak

Pre-season projections from Tyler Bozak were fairly conservative. Dobber had him bagging 55 points in 70 games, the Forecaster had him as high as 63 points in 75 games, with an average projection of 54 points in 71 games, among all sources.

Instead, Bozak has eight points in the last five games, lifting him to 23 points in 24 games on the season, leaving many people with the impression that the Leafs have truly found a center worthy to line up next to Phil Kessel.

An analyst at Pension Plan Puppets known as draglikepull doesn’t see it that way, however. Despite Bozak’s hot start, he’s sticking to the pre-season projection of 55 points, and crunched a lot of numbers to back that up. I really like what he’s done here, and serves as an excellent example that could be applied to others as well.

For another view, James Mirtle of the Globe and Mail also took a run at this topic this week. Not only is he also concerned that Bozak’s sky-high on-ice shooting percentage could mean that his scoring is unsustainably high, but he’s also troubled by Bozak’s poor possession numbers and weak defensive play.