Kukla's Korner

The Puck Stops Here

Combining Zone Starts And Corsi Number

In my sabermetrics and hockey posts this summer, I have introduced the concepts of the Corsi Number and of zone starts.  Corsi Numbers measure the number of shots directed at goal (including shots on goal, missed shots and blocked shots) and zone starts measure which region on the ice that a player is in when he is on the ice for a faceoff.  It should be clear that if you start frequently in the offensive zone that you should see a benefit in your Corsi Number as a result.  Similarly, if you take a lot of faceoffs in your own zone, it should hurt your Corsi Number.  This is one thing that can be adjusted for.  In fact, objective NHL has done this.

It is relatively easy to determine from the available data that and offensive zone start is worth about 0.6 Fenwick (where a Fenwick is similar to Corsi except it does not include blocked shots).  When we include blocked shots (Corsi) this factor is about 0.8.  This is an approximate factor that should vary with time, defensive schemes, who takes the faceoff etc. but it is a useful number for adjustments.  Essentially it says that for each offensive zone faceoff, on average 0.8 shots are directed at the goal (or for each defensive zone faceoff 0.8 shots are directed at your own goal).  In some cases no shots will be taken.  In other cases multiple shots (i.e. rebounds) will be taken.  In some cases a defensive team might win the faceoff but fail to clear the puck and then the shot will be attempted.  With this factor, we have a method to try to correct for the way a player is used by his individual team.  It can be corrected by itself or alongside team corrections.  I will try both in the future.

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About The Puck Stops Here

imageThe Puck Stops Here was founded during the 2004/05 lockout as a place to rant about hockey. The original site contains over 1000 posts, some of which were also published on FoxSports.com.

Who am I? A diehard hockey fan.

Why am I blogging? I want to.

Why are you reading it? ???

Email: y2kfhl@hotmail.com