Balanced Corsi Relative and the Calgary Flames

Before I start this post in earnest- I need to give due credit to Eric T. (homophone brother!) over at Broad Street Hockey for compiling all the stats and coming up with an amazing spreadsheet for this. He's got a terrific post explaining in more detail how the stats I'm about to reference are derived, and I suggest you go read it here right now and just ignore the parts about the dirty Flyers players (kidding).

Corsi is a terrific statistic. The very basic explanation is that it matches up shots for versus shots against, indicating who's driving possession rather than who's riding luck or good circumstances. It's a bit more involved than this, but there's plenty of information available elsewhere explained by better writers.

So if it's so great- what's all this "balanced" and "relative" nonsense?

Simply put- the balanced adjusts for starting location and the relative means that the number is relative to other players on the team, eliminating hangerons on the top teams (think Tomas Holmstrom playing with Pavel Datsyuk. Good player, but he’s not driving the bus there).

So balanced relative corsi largely takes a look at who's moving the puck in the right direction, while accounting for where they take faceoffs. It's harder for a player to record a shot on net if they're starting in the defensive zone a lot, and it's easier to do so if all the faceoffs they're on the ice for are in the offensive zone. (As I mentioned in the paragraph up top, I highly suggest reading the article this is based on first. Just good stuff.)

And so- here is a look at the Calgary Flames and Balanced Relative Corsi.

It’s certainly an interesting look at who’s driving the puck. Now there’s a couple things to remember that statistic doesn’t take into account. First, we know who plays what level of competition. You can look at Behind the Net’s QCOMP stats to confirm, but Jackman and Backlund are basically playing scrubs and knocking the ball out of the park against them.

Most of the numbers we see here about lineup with what we know. Alex Tanguay and Jarome Iginla rarely crush the competition in possession and Rene Bourque has just had a horrendous year. The interesting outlier here to me is Cory Sarich. He’s pretty often maligned, and rightly so. But nonetheless, when he’s on the ice, the puck isn’t moving in the wrong direction as much as you’d expect given his zone starts (OZ% of 48.3%, expected relative corsi of -0.42). I’d have to run some WOWY scripts to double check on this, but my expectation is that when he plays with Mark Giordano in the offensive zone, the possession metrics are through the roof, and when he’s away from Gio, there’s a giant fall.

The true players that really excel based on both this metric and the level of competition they regularly face are the aforementioned Mark Giordano and David Moss. Not only do they pass the stats measurement, when they’re on the ice, it’s noticeable by eye in a very good way. At some point this summer I’ll try and run these numbers using Fenwick numbers instead (which don’t count blocked shots) and I’m sure we’ll see a spike for Giordano.

by Arik Knapp