I have written a few controversial pieces here at HockeyAnalysis.com (for example, my post on Luke Schenn back when Leaf fans thought Schenn was the best thing since sliced bread) and I suspect this might generate some controversy as well because of the conclusions made about Zetterberg’s weak defensive ability. I also want to do this post to show how I believe we should be doing player evaluation because I believe that most people evaluate players in a poor way.
The first thing I believe is that we must evaluate players based on goals and not corsi/fenwick/shots because there is ample evidence that players can influence shooting percentage (for example here and here) and there is some evidence that players can influence save percentage (for example here). Because of this, conducting a corsi based analysis will not give you a complete view of a players ability, and I think you will see some of that with Zetterberg. Furthermore, I believe to get a more full and complete understanding of a players abilities we need to evaluate the players defensive ability and offensive ability separately which is what I will do.
As we are dealing with goal data which can fluctuate from season to season it is best to conduct a multi-season analysis to observe the greater trends, not what could be somewhat luck driven single season results. Let’s start by looking at Zetterberg’s goals for per 20 minutes (GF20) and goals against per 20 minutes (GA20) on-ice stats and see how they rank league wide and on the Red Wings.
|Year||GF20||Team Rank||League Rank|
|2011-12||1.157||3 of 11||21 of 312|
|2010-11||0.931||6 of 12||99 of 321|
|2009-10||1.073||1 of 10||34 of 319|
|2008-09||0.860||7 of 12||135 of 318|
|2007-08||1.193||2 of 12||16 of 312|
|2009-12 (3yr)||1.054||27 of 295|
|2007-12 (5 yr)||1.045||23 of 274|
The data above is for 5v5 zone start adjusted ice time and the ranks are among forwards with 500 minutes of ice time for single seasons, 1500 minutes for the 3 year average and 2500 minutes for the 5 year average. As you can see, from the league-wide rankings we are taking the top 9 or 10 forwards on each team so we are getting the majority of the players who get regular shifts in the NHL. As you can see, offensively Zetterberg performs quite well and while there is some year to year fluctuation, the overall trend is that he has awfully good on-ice offensive numbers. Now let’s take a look defensively.
|Year||GA20||Team Rank||League Rank|
|2011-12||0.840||10 of 11||193 of 312|
|2010-11||0.969||11 of 12||278 of 321|
|2009-10||0.970||9 of 10||275 of 319|
|2008-09||0.795||7 of 12||158 of 318|
|2007-08||0.638||10 of 12||65 of 312|
|2009-12 (3yr)||0.924||261 of 295|
|2007-12 (5 yr)||0.845||184 of 274|
Defensively, he is not only generally among the worst on his team, he is generally speaking among the bottom half of the league, or worse. Over the past 3 seasons he ranks 261st of 295 players in terms of GA20 which puts him in the bottom 12 percent which to many I think is surprisingly bad.
A lot of people will now start screaming something like, yeah, but he plays against the oppositions best lines which is certainly true but there are two things to remember. First, he also plays with some pretty good players, and quality of competition is not nearly as important as most people believe. But, for argument sake, let’s take a look at Zetterberg’s quality of teammates and opposition.
|TMGF20||0.863||11 of 295||0.902||4 of 274|
|TMGA20||0.753||25 of 295||0.715||5 of 274|
|OPPGF20||0.804||31 of 295||0.801||47 of 274|
|OPPGA20||0.782||22 of 295||0.782||30 of 274|
TMGF20 is a weighted average (by ice time played with Zetterberg) of his team mates GF20 when they are not on the ice with Zetterberg. TMGA20 is the same for GA20 and OPPGF20 and OPPGA20 is a weighted average (by time on ice playing against Zetterberg) of his opponents GF20 and GA20 when they are not playing against Zetterberg. So, what you can read from the above table is yes, Zetterberg plays against pretty good quality of competition, but he also plays with outstanding teammates, and the quality of his teammates will have a far greater influence on his stats than the quality of his competition (just look at how the values of TMGF20 and TMGA20 compare to OPPGF20 and OPPGA20).
The next step is to dig deeper into whether how his line mates perform while on the ice with Zetterberg and when they are not on the ice with Zetterberg. The table below shows each players GF20 when they are playing with Zetterberg and when they are not playing with Zetterberg for each player who has played at least 150 minutes with Zetterberg in the season identified.
Generally speaking Zetterberg’s teammates have better offensive “on-ice” numbers when Zetterberg is on the ice with him than not. Of the 22 player seasons listed above, 12 of them produced more offense with Zetterberg than without and more importantly the average improvement was 11.4%. Now lets look at Zetterberg’s defensive numbers, GA20.
Only 6 of the 22 player seasons listed above did the player have a better (lower) GA20 when playing with Zetterberg than when not playing with Zetterberg and on average when teammates played with Zetterberg their GA20 rose a whopping 23.8% which seems to me to be quite significant.
Another thing we can look at is GF% which is the percentage of goals scored while the player was on the ice that were goals by his team. GF% is goals for divided by goals for + goals against. GF% can give you a more complete view of the player.
Of the 22 players seasons listed above, only 9 of them saw the player perform better with Zetterberg than not with Zetterberg and the average was a drop in GF% from 58.1% to 54.7%.
There is a lot of stats and numbers listed above and a lot of things to consider when evaluating a player so I have tried to come up with some all-encompassing stats to help give us a high level over view of a players on-ice performance. These are HARO+, HARD+, and HART+ which stand for Hockey Analysis Rating Offense, Hockey Analysis Rating Defense and Hockey Analysis Rating Total (the + stands for the enhanced version). Here is how Zetterberg ranks in these:
|2011-12||1.353||29 of 312||0.882||216 of 312||1.117||64 of 312|
|2010-11||1.110||119 of 321||0.813||279 of 321||0.962||195 of 321|
|2009-10||1.316||27 of 319||0.802||284 of 319||1.059||98 of 319|
|2008-09||1.014||161 of 318||0.948||167 of 318||0.981||181 of 318|
|2007-08||1.426||21 of 312||1.034||122 of 312||1.230||30 of 312|
|2009-12||1.246||29 of 295||0.846||269 of 295||1.046||99 of 295|
|2007-12||1.094||26 of 274||0.899||227 of 274||0.997||71 of 274|
When considering these stats, anything above 1.00 is above average, anything below 1.00 is below average and these take everything into consideration (on-ice stats, quality of teammates and quality of opponents) and are for 5v5 zone start adjusted situations.
So, what does this make Zetterberg? Clearly Zetterberg is a top end offensive player, but he is also a sub-par defensive player. When you add it all up his overall rankings puts him as a borderline first line player (ranks 99th of 295 in HART+ over past 3 seasons) who should be playing in offensive situations, but not be given top defensive responsibilities. This is kind of how he has been used. Although there is some year to year fluctuation, on average over the past 5 seasons 32.3 percent of his 5v5 zone starts have been in the offensive zone, 30.0% in the defensive zone and 37.7% in the offensive zone. That said, he has faced very good opponents in terms of GF20 so that might not be optimal use of his talents and matching him up against less offensively gifted competition would probably be a wise decision.
(Note: I will leave it as an exercise for the reader, but if you conducted a corsi analysis instead of the goal analysis above you will probably find very different results, but I just think goals are more important).