Clutch and Grab! Clutch and Grab! (via www.capitalareafootball.nb.ca)
There has been some chit, and chat, around the internet watercoolers the past few days about the decrease in goals since the lockout and why that might be. First, I saw this tweet by Neil Greenberg on how powerplays per game are at a three decade low. Then, Ed Willes penned (typed?) this article on the same subject, theorizing that defensively minded teams are also contributing to the lack of scoring. He tapped the Sedins for some quotes. Finally, SkinnyPhish at Pension Plan Puppets slammed Willes' piece, saying that the only reason for the decrease in scoring was an increase in the skill of goaltenders, taking some uncalled for swipes at the Sedins just for fun in the process.
The trend of goals per game decreasing back to levels right before the lockout intrigued me, so I decided to really look into what is going on.
First up, let's take a look at the common thread here: Are powerplay opportunities down? Well, yes.
(note: in all graphs, PRE refers to pre-lockout)
This one is pretty obvious. Powerplay opportunities are way down since the lockout, down so much that the past few years there have been fewer powerplays per game than even before the lockout. Now, who knows what the reason for this is. Is it because players are learning what not to do? Probably. Or it could also be that refs are letting more things go. Tony Gallagher probably subscribes to the second theory, especially in relation to the Canucks. I don't think there is any way to actually determine the cause (of reduced powerplays, not of the conspiracy).
Next, let's look at goals per game, broken down into power play goals, and even strength goals (minus empty net and penalty shots).
What do we have? Overall goals per game are down, basically back to pre-lockout numbers. This is driven completely by the decrease in powerplay goals per game, as even strength scoring has only increased very slightly. Of course, with much less time being spent on the powerplay, we would expect there to be fewer power play goals. In the same manner, less powerplay time = more even strength time, so we should expect even strength scoring to increase.
Let's look at the goals per 60 minutes for even strength and PP to see why:
(note: there is no data on PP time before 2003)
This is the most interesting graph to me. Even strength scoring per 60 minutes of even strength time has remained basically constant in the past decade - even prior to the lockout. Powerplay goals/ 60 are kind of all over the place, but without that outlier in 2010 the scoring rate on the powerplay has also remained fairly consistent. I don't know what the bottom line here is: Clutch and grab didn't reduce even strength scoring as much as people thought? Because it's stayed at the same rate since all that stuff was supposed to have been removed.
Finally, to the theory that "goalies just got better": Skinny just looked at overall save percentage and saw it going up. It's pretty well known that save percentage while short handed sucks, so fewer powerplay opportunities should lead to fewer powerplay goals and better SV%. First, shots:
Not much to see here really. Total shots per game are fairly constant, the decrease in powerplay shots being offset by the increase in even strength shots. Total shots are up since the lockout, so there is that. Now, onto save percentage:
As expected, save percentage while shorthanded has gone up up up since the lockout, which is directly related to the decrease in powerplay opportunities and goals. Don't know what happened in 2010. Or 2009 for that matter. Although there was a jump in powerplay opportunities from 2009 to 2010, so that could partially explain it.
Even strength save percentage has increased slightly, up .0036 since the lockout while SH sv% is up 0.016.
So, is an increase in skill of goaltenders the reason why scoring is down? Or is it a reduction in powerplay opportunites and goals causing better goalie numbers while shorthanded? And of course, is that all goalie skill, or is it being helped by defensive systems (which Skinny rejects outright)?
I don't have enough data (I don't know if anyone really does) to prove or disprove why the even strength save percentage is slightly increasing, and increased goalie skill is possible - although I will say this: prior to the lockout, EV save percentage increased dramatically, which everyone pretty well attributes to clutch and grab and the trap. So I don't see why that should be completely ruled out here.
Unless you think Brian Elliot all of sudden took in the spirit of Dominik Hasek.
Data from NHL.com