For those who love the game of hockey, and are fans of the Edmonton Oilers, in particular, we’re constantly searching for various statistical metrics for evaluating our players. In most cases, the ‘measure of a man’ is how well a player performs at even strength or ‘EVs’. Currently, there are various statistical methods for getting an idea of how well a player actually does perform at even strength, though there are often flaws and limitations with each method.
Conventional methods for evaluating how well a player performs at EVs often are not limited to, but include (Goals For-Goals Against), plus/minus rating, or Corsi numbers. Corsi numbers are an interesting stat. The Corsi number is generally a measure of the number of shots directed towards the net while the player is on the ice (typically, the number directed towards opposing team’s net – the number directed to your own net). Since there are far more shots in a hockey game than actual goals, the Corsi number has the potential of being a more accurate than a simple +/- number due to the larger sample size of data. Typically, the Corsi number is 4x more accurate than the +/- number. However, one of the limitations of the Corsi number is that it can be skewed by where a particular player starts on the ice. For example, if a player often starts in his own defensive zone, it will adversely affect his Corsi number.
Recently, while reading the excellent blog, Puck Prospectus, I came across a new and interesting ‘advanced stat’ to measure player value at even strength. Intrigued by this new metric, I emailed Timo Seppa (the author of that article) asking him if he could kindly provide me with this data for the Oilers roster players for last season. Timo promptly send me a reply with the data and for that, I am very appreciative (thanks again, Timo). I will now do my best to present this data.
As Timo said, “Say hello to ESTR“ (I wonder if he got that line from Scarface?).
Even Strength Total Rating (ESTR) is a more advanced version of Goal Difference per 60 minutes (GD/60), taking into account the quality of teammates and quality of opposition for all non-empty net Even Strength goals scored while a player is on the ice. ESTR is a sum of its components, Even Strength Offensive Rating (ESOR) and Even Strength Defensive Rating (ESDR), which are Goals For per 60 minutes (GF/60) above average and Goals Against per 60 minutes (GA/60) above average, when adjusted for teammates and opposition. To get ESTR and its components for each player, goal difficulties for all goals over the course of a regular season (or postseason) are calculated, weighted by the base GF/60 and GA/60 of the players on the ice. For each player’s GF and GA, the average goal difficulty the player was on-ice for is then applied against each player’s base GF/60 and GA/60 to get their ESOR, ESDR and ESTR.
In short, ESTR is the number of goals per 60 minutes of ESTOI that the player is worth at Even Strength, given NHL-average players as teammates and opposition.
- Essentially, higher numbers of ESTR, ESOR, and ESDR reflect that a player is comparably more effective than an average player offensively (ESOR), defensively (ESDR), and overall (ESTR) at even strength.
- ESTR= ESOR + ESDR
To provide context for these ESTR numbers, the first table includes the top 3 ranked players for the 2008-09 season based on ESTR along with some other notable players
Table 1 (click link for more data)
***For players who played more than 500 min of even strength ice time (ESTOI)
Table 2 – Ranking of the Edmonton Oilers roster for 2008-09 by ESTR
Well, in comparison to the first table, we don’t currently have a player that ranks in the top 20 in the league at even-strength with respect to the ESTR ranking. However, what’s interesting, is that Dustin Penner at +0.93, based on this metric, is not only the best even strength player on our roster, but he’s not too far off of the surprising Rene Bourque at +1.18 (rank 20th). Secondly, I would be remiss if I didn’t include Timo’s comment in the email which was that for all of our players who played less than 500 minutes (ESTOI), they were all negative. Timo remarked that this reflected good coaching (MacT).
Consistent with the opinions of the Oiligosphere, the Edmonton Oilers current roster of players does not have a wealth of players who are particularly strong at even strength. Last season, we only had 10 players on our roster who kept their head above water at even strength based on ESTR. Four of our top ten players at ESTR were defensemen. Based on this data, it’s understandable how much Lubo’s injury hurt our playoff chances. I wrote a previous post on Lubomir Visnovksy which is consistent with the impact of his even-strength play on Hemmer’s game.
Much like Dustin Penner, Robert Nilsson is subject to plenty of criticism regarding his level of play. Also like Penner, his boxcar numbers are less than inspiring (64gp, 9-20-29). Admittedly, lately I’ve been among the masses who were willing to send Nilsson and his $2million cap hit packing. In contrast to my own sentiments and many among the Oiligosphere, this data suggests that Robert Nilsson is a valuable player at even strength.
If you’re an Oilers’ fan, chances are that you love Sam Gagner and have high hopes for what he can bring to this team. I myself was surprised to see Gagner ranking in the top 5 on our current roster of players based on ESTR. Based on ESTR again, it’s perhaps less surprising that we’ve let go of both Kotalik as well as Brodziak.
Again, special thanks to Timo Seppa over at Puck Prospectus for providing me with this data. To see more articles by Timo, click the link. As well, Timo has his own blog site, Ice Hockey Metrics, that you can visit by clicking the link on that text.
***Update, Timo’s written his own blog on this topic: Striking Oil: Edmonton’s Best.