While preparing statistics for a few upcoming posts on on-ice contributions, I decided to do a quick study on the share of on-ice shot attempts taken by defensemen versus forwards. The metric I’m using, which is a spin-off of an old one whose name doesn’t quite capture it right, is what I’m calling on-ice shooting proportion, or OSP. The results were quite interesting, and I decided that I should test the data a little further and see what we could find.
For this post, I focused on 5v5 ice time for two reasons: 1) it comprises the overwhelming bulk of on-ice play (about 80%), and 2) it’s less likely to be artificially boosted by something similar to a blueline-driven powerplay approach. The first graph that caught my eye focused on comparing the entire forward and defenseman populations, from 2007-08 through 2014-15:
That certainly looks like a trend to me. Generally speaking, the average defenseman contributed 16.2% of all on-ice shot attempts this year; keep in mind, in a 5v5 situation with an even distribution of OSP among all players, you’d be at 20%. I wanted to dig deeper, though, and see if there was any differences between top players and the bottom.
The uniformity in that trend is remarkable. Teams are either a) having their defensemen shoot more often, or b) choosing defensemen who tend to shoot more often. Either way, it’s generating a greater share of attempts from the point, and it’s coming from the top on down.
Not quite satisfied, I decided I wanted to test this hypothesis a little further, this time looking at assists. Taking on-ice goals-for, I looked at what proportion of those goals were either first or second-assisted by the forward and defenseman populations:
While second assists seem to vary (though overall slightly trending up for defensemen), the first assists are, again, pretty clearly on the move. You’re going to have to bear with me on the next one, because I again split the groups into top to bottom lines and pairings:
The second assist groupings, as you can see, are a real mixed bag, so much so I don’t even think the overall forward vs. defensemen trend is convincing. On the other hand, let’s look at those first assist groupings a bit closer:
While the defensive third pair is a bit up-and-down, the first and second are clearly on the move, in the opposite direction of the first and second forward lines. The third forward line is mixed, but the fourth forward line is pretty astonishing. Remember the third graph from my post on parity? In it, the zone starts for the top 3 forward lines seemed to only have slight trends, but the fourth showed a pretty drastic drop in zone starts over the years, suggesting teams have moved towards a sort of defense specialization for them. That’s certainly supported by their drop-off here.
Chalk this up to another potential impact of the pressure of parity, and the demand for control of the puck. Teams are gradually realizing that they need more-complete defensemen — ones that can move the puck, not merely stop it — and whether by strategy or selection, they’re getting it.