I often hear hockey broadcast commentators singing praises for the gritty, stay at home defensemen on whichever team happens to be playing. Every time Gleason drops a knee to get in front of a shot, the Leafs fan base explodes with comments of “that’s why we traded for him!” or “that’s the type of playoff commitment we need from the rest of the roster!” I’m not entirely convinced the stay at home defensemen have any significant value at 5v5 to the club they play for when compared to offensive minded counterparts. There seems to be a culture around defensive defensemen that they help the team win by preventing goals against. For this reason, they are often played over puck moving and skilled defensemen. However, I would assert that these defensive defensemen do very little in ways of helping the team compared to their skilled counterparts.
The argument I hear in favor of purely defensive d-men is that they prevent goals. What this boils down to is preventing shots – or as some would argue, improving their goalies by giving up less quality scoring chances. Let’s take a look at the former.
I’ve collected some data and put together a few charts to show why I think the claim that purely defensive defencemen are better at preventing shots against than offensive defencemen is false. Below we see examples of defencemen that are skilled in the offensive zone but often criticized for their defensive zone play compared to ones who are criticized in the opposite fashion. First is a comparison of Tim Gleason and Jake Gardiner on the Maple Leafs.
Gardiner allows two less shots against per 60 minutes of play than his counterpart Gleason, who allows roughly two thirds of a shot against more than his team average.
Douglas Murray is often criticized for being incredibly slow and not really good at hockey, yet he remains employed by NHL teams because of his reputation as an effective stay at home defensemen who will throw the body around and get in the way of shots. Yet, while he is on the ice, the opponents generate an average of 3 shot attempts more than when P.K. Subban is one the ice – Subban who is oft criticized for thinking offense first at the expense of defensive positioning. While Murray is on the ice, the Canadiens allow .6 more shots against per 60 minutes than their team average.
The Flyers average 30 shots against per game. With Nicklas Grossman on the ice, they average 32. Meanwhile, aging but offensively talented Kimmo Timmonen averages 28 shots against per 60 minutes, 4 shots less than defensive-minded Nicklas Grossman.
The three defensive-defensemen I have singled out all have one thing in common; their valued for their size, grit and ability block shots and hit hard. However, the evidence shows that while they may have these qualities, said qualities are not leading to a decrease in shots against. Meanwhile, the offensive minded defensemen – all of whom have been criticized for poor defensive play — are actually faring better in reducing shots against. The explanation for this is not necessarily that they are doing a better job of defending. Instead, it could be asserted that these offensive minded players are better at creating offense and as a result spend less time in their own defensive zone. It’s not that they aren’t necessarily liabilities in their own zone, more so that they make up for it with their play everywhere else.
The question is then raised that if defensive minded D-men don’t reduce shots against, why are they valuable? Why not employ purely offensive defencemen? The argument against this is one that I again disagree with; that argument is that defensive defensemen give up less quality chances. If this were true, then their goalies save percentages would be better with them on the ice. Let’s see if this holds true using the same sample players as above.
Right off the bat, we see that the assertion that defensive defensemen reduce quality scoring chances against is likely untrue. Anyone who watches Jake Gardiner knows that he often thinks offense-first and allows odd man rushes as a result, yet his on-ice save percentage is considerably higher than Gleason’s. This would imply that Tim Gleason does not in fact reduce quality scoring chances against his team. If he did, it would lead to a higher save percentage than the team average – and yet it does not.
Again, we see that the defensive defensemen’s on ice save percentage is not significantly higher than the team rate and in this instance is actually significantly lower. Subban’s is considerably higher than Murray’s, despite being often criticized for lackluster defensive play.
Once again we see the defensive defensemen does not improve the performance of his goaltender, as Grossman’s on-ice save percentage is considerably lower than the average for his team and even lower than Timmonen’s. There is little to no evidence that any defensemen in the NHL has the ability improve his goaltender, so these results are not particularly surprising. Regardless, this small sample size of players points to a larger conclusion; defensemen, or any player for that matter, has little to no impact on the performance of his goaltender. On-ice save percentages deviate very randomly as well, making it even harder to draw meaningful conclusions from nearly any sample size.
These three case studies are consistent with league wide trends and what I would have assumed the results would be. Defensive defensemen typically allow more shots against than offensive minded ones across the league and this is shown in these three case studies. Seeing as players have no effect on their goalies save percentage – there is no solid evidence that players can have this ability – it shows that the only thing a defensemen can change for their team’s goals against is reducing shots against. As the offensive defensemen mentioned actually limit shots against more effectively than their defensive counterparts and as this is consistent with league wide trends, it shows that defensive defensemen are not as effective at reducing goals against as seems to be perceived. Defensemen who play only defensive-minded games are simply not as valuable as offensive defensemen no matter which way you look at it, even when one is only considering limiting goals against. Being offensive seems to in fact be a good defense – being in the opponents zone constantly is an effective way to reduce shots and goals against. National Hockey League General Managers value defensive defensemen as they believe the qualities they possess limit goals against. It seems obvious, however, that these qualities may be good in the defensive zone but do not create good hockey players over all or even at reducing shots and therefore goals against overall. For this reason, General Managers over value defensive defensemen on the grand scale and would likely have more success by employing a higher proportion of offensive, puck moving defensemen than large, big bodied ones such as Tim Gleason, Douglas Murray or Nicklas Grossmann. I’ve come to this conclusion only by looking at shot against totals; when one looks at the shots for numbers, the totals are staggeringly in favor of the offensive minded defensemen, which almost goes without saying. Puck moving defensemen are significantly more valuable than their defensive minded counterparts, even when it comes to reducing goals against and as such one dimensional defensive defensemen should not be valued nearly as highly in the NHL trade market or overall.