Quantifying The Injury Woes

by J.P. on Dec 4, 2008 11:25 PM EST

A thread on the Caps message board pointed to an interesting post on the Behindthenet Blog regarding the cost, points-wise, of losing top players.

Basically, over the past five seasons, teams have lost 3.07 standings points per 82 games for every ~19 minute forward and 8.44 standings points per 82 games for every ~21 minute defenseman missing from the lineup.

It just so happens that the Caps have a few players out of their current lineup who fit the bill, so let's see what these injuries have cost the team:

Player	POS	TOI/G	Games Missed	Points Lost
Mike Green	D	25:13	8	.82
Tom Poti	D	22:07	9	.93
Alex Semin	F	19:11	10	.37

In other words, the Caps have likely lost more than two points in the standings already due to the injuries to these three players alone (and this doesn't even include 20-minute man Jeff Schultz or 18.5 minute guy Sergei Fedorov's absences).

Put another way, for each game this trio misses, the Caps lose nearly a quarter of a point in the standings - tonight's win over the Islanders, then, really only netted the Caps 1.75 points.

Obviously, actual mileage may vary here, but one thing is pretty clear - as the injuries pile up, so do the lost points, and while the Caps may get those players back at some point (hopefully soon), those points are lost forever.

Tweet Comment 10 comments | 2 recs |

Do you like this story?

Comments

Quantifying injuries

interesting formula, but it removes all subjectivity and other factors out of the equation like experience (not necessarliy playing time – is losing Fedorov more costly than losing Semin? I’d submit it might be) of the injured player, and also assumes the effect is linear, not taking into account the cumulative effect – meaning, losing two core defensemen (Green and Poti) at the same time might be worse that losing Green for eight games, having him return, and then losing Poti for nine games. Also, the effect stands to be greater on the Caps than is does on the Lightning or Thrashers, as they were less like to accumulate those points in the first place.

Interesting to ponder however. I wonder if those other factors could be introduced, and weighted in some way.

by shotfromthepoint on Dec 5, 2008 7:45 AM EST reply actions

interesting formula, but it removes all subjectivity and other factors out of the equation

Absolutely right. This is a very, very raw statistical application.

It also serves to confirm, in my mind, that if the Caps could get one guy back right now (a question we were discussing the other day), it’d be best to get Green healthy and, in fact, would probably be better to have Poti back in the lineup than Semin.

Japers' Rink: Hockey blogging from the most powerful city in the world

by J.P. on Dec 5, 2008 7:58 AM EST up reply actions

(It also means that with Gonchar and Whitney out, the Pens have probably lost five points or so in the standings, for what that’s worth).

Japers' Rink: Hockey blogging from the most powerful city in the world

by J.P. on Dec 5, 2008 8:00 AM EST up reply actions

I had the opposite reaction – the numbers are interesting but I don’t think they actually tell you a whole lot.

I may be misunderstanding the methodology but to me it looks like we’re just talking about correlation between points per game changes and guys out of the lineup; I didn’t see that there was any method of isolating the effect of the missing players by accounting for things like back to back games, quality of opponents, home versus away, use of backup goaltenders,etc. That’s not to fault the author because I still think it’s very cool that he’s put together the numbers, but there are so many unknowns and unaccounted for variables that it’d be hard to take anything away in an objective sense other than teams perform worse without their best players.

If I had to guess, I’d venture that the effect is multiplied when more than one guy is out of the lineup. For example, by the numbers Poti’s lost time may have cost the Caps .93 points and Green’s .82 but I’d be willing to bet that having both of them out of the lineup on a number of nights has cost the Capitals more than 1.75 (really just one, b/c you’d round down here) point.

by David Getz on Dec 5, 2008 12:51 PM EST up reply actions

Well, the more games these guys miss, the more accurate the predictions would be, presumably, because over, say, ten games you’d have some back-to-backs, some good and bad teams, etc. Over two games? No. Really, it’s just a case where a larger sample size would give a truer result, which it should.

But I do agree that the overlap/cumulative effect isn’t accounted for here. Like I said, “actual mileage may vary here, but one thing is pretty clear – as the injuries pile up, so do the lost points.” I don’t think anyone’s disputing that fact, we’re just trying to get a handle on just how many points are slipping away.

Japers' Rink: Hockey blogging from the most powerful city in the world

by J.P. on Dec 5, 2008 1:11 PM EST up reply actions

I agree, the sample size goes a long way towards establishing the validity of the results and I do think the data set used (five seasons) was large enough.

What I meant to do was just to comment that I don’t think it removes all subjectivity or other factors from the equation because it doesn’t isolate the effect of the lost players, it gives the correlation between lost players and points per game. That point and the bit about the cumulative effect of the injuries were separate trains of thought and I should have established that in my first post so as to not give the impression I thought it was being ignored.

by David Getz on Dec 5, 2008 2:03 PM EST up reply actions

Combination Factor as well

Of course losing an individual makes a difference, but when you lose several starters who each pile up big minutes, I can only imagine the numbers are far worse.

by OvechkinLaichsSemin on Dec 5, 2008 8:20 AM EST reply actions

You’d think so.

These numbers are based on the simple proposition that when top guys are out, other guys are pressed into roles for which they’re not necessarily well-suited (and it’s why they only look at ~21 minute guys, as the drop off from a 14-minute guy to his replacement isn’t nearly as significant). When a #2 guys is playing #1 minutes, there’s a drop off. When it’s a #3 guy playing those minutes (and so on), the ripple effect would obviously be greater.

Japers' Rink: Hockey blogging from the most powerful city in the world

by J.P. on Dec 5, 2008 8:29 AM EST up reply actions

That’s pretty f’in brilliant. The Caps current situation is probably costing them ~half a point a game, all things considered then, eh?

Modern Art Notes

by TylerG on Dec 5, 2008 9:36 AM EST reply actions

I doubt it’s quite that much. Granted, the overlap likely makes it more than any one injury on its own, but when you start accounting for the lost points cost by Erskine’s injury, that’s negligible.

Japers' Rink: Hockey blogging from the most powerful city in the world

by J.P. on Dec 5, 2008 10:15 AM EST up reply actions