League Equivalencies and NHL Rookies

July is obviously quite a dead time for hockey of all disciplines, I'm looking forward to the tournaments upcoming in August that's for sure. We've got a Canada-Russia U20 series, the U18 Ivan Hlinka Memorial, a Lake Placid U20 tournament featuring the USA, Sweden, and Finland, the European Trophy (starting today for some reason with one game), and the second edition of the World Junior Club Cup. August is positively bumping with hockey action, believe it or not.

In the meantime, I've been expanding on some of the work I did last summer with league equivalencies. I'm working on using Sweden's Elitserien as a standard this time around, with a long term goal of getting a more accurate read on the league ratings with a kind of cross-league index. I'm more and more focused on the ages of players and the improvements that can be expected.

For those that aren't familiar, league equivalencies are a predictive model that tries to see how much of one's offensive output can carry over from one league to the next. It was a concept that Gabe Desjardins of Behind the Net developed and I did quite a bit of work on last summer by using the KHL as the standard league for the first time. Most of these studies have focused on using the NHL or North American based leagues (such as the NCAA to get a read on the USHL's quality), but the European leagues had kind of been neglected. My findings last year indicated that European offence is not as translatable to the NHL as it used to be, indicating a growing gap between the North American and European leagues.

More importantly, for people wanting to track the growth of NHL prospects, I am starting to be able to assign metrics for European second tier and junior leagues.

I recently did an interview with the Sabermetrics Network that focused on equivalencies and applying them to next year's crop of NHL rookies. In doing this, I decided I'd take a look back at the past four years of NHL rookies to gauge how well the models worked.

There are a decent amount of guys that produced double digits more or less than predicted. However, that's not just the case with rookies in any given season, either. Circumstance, luck, playing on a top PP, playing with elite linemates right off the bat... these are all factors that contribute to such wild fluctuations.

The metrics I'm using here are all age-adjusted except for the European league ones, which are ones I came up with via my KHLE work last season. I'm not terribly confident in either my SEL or SML number right now, but based on my own research that's the best I can do. Scott Reynolds did the legwork on age-adjusted NHLE's, which reward players for having productive seasons at various levels at a younger age. I'd like to be able to do something similar with European league ratings, but for now assume someone like Tarasenko, Silfverberg and Granlund are underestimated right now with their metrics, as that is the overall average for players in those respective leagues. Roman Cervenka, a veteran at over 26 years old, probably has a very accurate rating.

I'm quite bullish on Schwartz, Tarasenko, and Palmieri as NHL rookies this coming season. Schultz is intriguing, that's for sure, but it should be noted that David Rundblad would've had similar projections coming out of Sweden last year but couldn't hack it in the NHL right away, it's very possible that Schultz will be similarly overwhelmed.

For those that missed it, here's my interview, led by Rob Vollman, who himself has done some great work with equivalencies.