The World Hockey Association

Summary

Further Junior Hockey Projections

Twenty years ago, almost all every NHL player was drafted from the Canadian Hockey League.  Even today, the majority of NHL draft picks still come from the three Tier I junior hockey leagues, the Western Hockey League (WHL), the Ontario Hockey League (OHL) and the Quebec Major Junior Hockey League (QMJHL).  But how does player performance translate from these leagues to the NHL?    

It is obvious that, despite drafting thousands of times, NHL scouting hasn’t adequately answered this question.  Looking at the 14^th-23^rd post-expansion drafts, from 1979 to 1989, 15 of 33 picks had careers that lasted more than 1000 games.  But NHL teams also used the second and third picks on players like Dave Chyzowski and Neil Brady, not to mention famous “busts” Doug Wickenheiser, Doug Smith and Perry Turnbull.  Even after 20+ years of evaluating CHL players, some teams looked at Vincent Damphousse and Adam Foote and decided they’d be better off with Brady and Chyzowski.

So were these errors easily avoidable?  That’s the question we’ll answer.

Junior League Parity

Some preliminaries: in the aggregate, there’s no significant difference between the three junior hockey leagues.  This table shows the League Difficulty of Juniors relative to the AHL and NHL:

The League Difficulty is the ratio of a player’s points-per-game (PPG) in junior to his PPG in the next season in the AHL or NHL.  While individual performances vary, the average player who moved from the OHL to the minors or the NHL played as well as the average player who started out in the WHL or QMJHL. 

The significance of Age

Does it matter how old a player is when he puts up big numbers in Junior?  Obviously it does – Wayne Gretzky had 70 goals and 112 assists in 64 games for the Sault Ste Marie Greyhounds as a 17-year-old in 1977-78.  Seven years later, Dan Hodgson had the exact same statistics when he was a 20-year-old playing for the Prince Albert Raiders.  Hodgson was drafted 83^rd overall despite his prolific scoring, and had 74 points in a 114-game NHL career.  (He is still active in the Swiss National League.)  At age 22, Hodgson had 57 NHL points; Gretzky had already scored 1024 points between the NHL and WHA.

So in a qualitative sense, it’s obvious in this case that a 17-year-old player’s performance predicts a much better career than a 20-year-old’s stats.  But there is also a strong quantitative relationship between past and future performance.  Based on the performance of thousands of drafted players, we can predict how many points a player will score in the NHL when he’s 21-years-old.  If he’s 17, four years later, we expect him to score at 72% of his junior rate.  But if he’s 20, on average, he’ll retain just 26% of his scoring. 

There is a caveat: younger players are a bit less predictable than older players.  For a 17-year-old, the middle 50% range of the projection is from 45% to 98%, while for a 20-year-old, it’s from 17% to 33%.  This wide range reflects how unpredictable future performance is for NHL players.  From age 21 to age 25, Wayne Gretzky scored between 196 and 215 points each season, which is only a 10% variation, while this method predicts a possible 2:1 variation in scoring.  The performance of an individual player is much more consistent than it is for the large group of drafted NHL players.

We could narrow the bounds of the projection if we had more data about the players.  This method tries to capture a player’s performance despite having no information about linemates, ice time, injury status, size and performance in other seasons.  Who you play with can have a profound effect on your performance: Rob Brown played with Mario Lemieux and had 49 goals and 115 points.  The Penguins traded him away two years later, and without Lemieux setting him up, he couldn’t crack an NHL roster.

PPG Projections by Age

This chart shows the ratio of NHL PPG to Junior PPG for forwards at each age.  The age is as of January 1st of a given season, i.e. any player born in 1961 is considered 18 years old during the 1979-80 season.

In the aggregate, players reach their peak performance level at age 22 and hold it for several years.  What’s most significant about this chart is what it implies about the age at which a junior player posts a particular PPG.  A 17-year-old player with 2 PPG in Junior can expect, on average, to score 1.5 PPG in the NHL at age 22, while an 18-year-old Junior doing the same thing has an NHL projection of 1.0 PPG, which is 40 fewer points over the course of a season.  This is the difference between elite players (Joe Sakic, Denis Savard, Dale Hawerchuk) and much lesser players (Jimmy Carson, Terry Yake, Mike Bullard.) 

This is very significant for the NHL Entry Draft.  An entire year’s worth of players become eligible for the draft, but the players born earlier in the year have a peak value 35% lower than players born late in the year.  This is obvious when you consider the difference that one year of physical maturity can make at age 17.  In evaluating a player, it is critical to keep in mind his exact age, down to his month of birth.

Back to the Beginning

Let’s look at a sample of star players and busts drafted with the first few picks:

In Junior, Chyzowski, Brady and Turnbull didn’t perform nearly as well as Hawerchuk, Savard and Lemieux, and this difference carried over to the NHL.  In the 1979 draft, teams had the option of drafting young players from Junior or from the WHA, which had signed away numerous underage juniors in 1978.  The WHA was nearly as good as the NHL at that point (see: League Translations) while the WHL (where Turnbull played) was only about one-third as good.  The Hockey News rated Turnbull as a top prospect, while ignoring former WHA players in their scouting. 

Sometimes, the differences can be more subtle:

Their pre-draft statistics look almost identical, but Damphousse was born in December while Wickenheiser was born in March, making him nine months older than Damphousse during the season.  Damphousse’s 2.25 PPG was accomplished largely at the same age as Wickenheiser had 1.38 PPG – a huge difference!  The key point is that just because two players are eligible for the draft in the same year, it doesn’t mean drafting teams can ignore age differences between the two players.

The USHL: North America’s Fourth Junior Hockey League

The United States Hockey League (USHL) is the only Tier I Junior Hockey League operating entirely in the United States.  Unlike the three junior leagues that make up the Canadian Hockey League, the USHL adheres to NCAA eligibility standards, which allows its players to continue on to college hockey before potentially moving on to professional careers.

Fifteen years ago, the USHL did not measure up to Tier I standards: it featured a lot of 9-6 games, and relatively few of its players continued their hockey careers along anything resembling a path to the NHL.  But as of 2006-07, nearly 10% of NHL players had also played in the USHL:

This is not surprising given that the number of USHL players moving directly to NCAA college hockey has been steadily increasing over the same time period:

At the same time, the caliber of USHL players relative to the NCAA has jumped substantially.  The plot below shows the relative points-per-game scored by USHL players in their first NCAA season.  The red line shows performance adjusted for the scoring levels in each league; blue is unadjusted.

As you can see, a point in the USHL has become 40-60% more valuable over the last fifteen years, assuming that the level of play in the NCAA has remained constant.  The translation from the NCAA to the AHL has been approximately constant during this era, so this is a safe assumption.  The average age of USHL players has also remained constant, which is especially significant given the dependence translations have on teenage players.

It is difficult to compare the USHL and Canadian Junior Leagues directly because the groups of players do not interact.  Few USHL players move to Canadian Junior (though they typically maintain their level of production), and virtually none move from Canadian Junior to the NCAA.  The table below shows the translations between leagues that commonly feed each other:

We can then estimate the translation from the USHL to the AHL by multiplying the translation from the USHL to the NCAA by the translation from the NCAA to the AHL:

The accuracy of the previous step is affected by a typical two- or three-year gap between a player’s last year in the USHL and first year in the AHL.  We can compare this to the observed translation from the USHL to the CHL for the relatively small number of players who played in both leagues:

It is clear that regardless of the analysis method, players who play in the USHL and CHL perform approximately the same once they get to higher-level leagues. Allowing for a year's worth of improvement, 18-year-olds in the USHL would maintain their level of scoring at age 19 if they transferred to Canadian Tier I Junior. Were they to transfer during the same season, they would likely maintain at least 80% of their scoring.

NAHL and Tier II Junior

It is important to keep in mind the gap between the USHL and non-Tier I junior hockey leagues.

League	to CHL	mean Age	to NCAA	mean Age
Tier II	0.45	17.3	0.33	19.4
NAHL	1.00*	16.9	0.50	19.6

* = small sample size

The USHL is clearly better than Tier II Junior Hockey.