There are two things that must occur to score a goal.  The first way is to get an opportunity to score and the second is to capitalize on that opportunity to score.  There are a number of statistics that we can use as a proxy for opportunity to score but one of the most common is Fenwick numbers which are shots + missed shots (some call this Corsi but I define Corsi as shots + missed shots + blocked shots).  We can then define the ability to cash in on opportunities as shooting percentage, or in this case fenwick shooting percentage.  So let me define the following:

Opportunity Generation = Fenwick shots per 20 minutes of ice time.

Capitalization Ability = Fenwick Shooting Percentage = Goals Scored / Fenwick shots

So the question I pose today is this:  What is more important in scoring goals, generating opportunities or the ability to capitalize on those opportunities.  To answer this I calculated each teams Fenwick per 20 minutes (opportunity generation) and each teams Fenwick Shooting Percentage (capitalization ability) and compared them to the number of goals they generated per 20 minutes of ice time and I did this for each of the past three seasons (I only considered even strength five on five data).  I also did this for both the offensive and defensive ends of the ice for a total of 90 data points offensively and defensively.

First for the offensive end of the game:

As you can see, shooting percentage (opportunity capitalization) has a much stronger relationship with scoring goals than getting shots (opportunity generation).  What about the defensive end of the game?

Again, opposition capitalization rates are much more correlated with scoring goals than opportunity generation.  In fact opportunity generation appears to have no correlation with giving up goals at.

The conclusion we can draw from these four charts is when it comes to scoring goals, having the ability to capitalize on opportunities (shots) is far more important than having the ability to generate opportunities (getting shots).  Controlling the play and generating shots does not mean you’ll score goals (just ask any Maple Leaf fan), having the talent to capitalize on those opportunities is what matters most.  From my perspective, this means the usefulness of ‘Corsi Analysis’ to be minimal, at least for the purpose of evaluating players and teams.  For evaluating goaltender workload, as it was initially intended by its originator former NHL goalie and Buffalo goalie coach Jim Corsi, it still has merit.

Every year we hear Leaf fans making the argument that they are a patient bunch and are willing to wait out a lengthy 5 year rebuilding plan and yet a mere 15 or so games into the season (and barely 40 games into the overhaul of the group of forwards) I am reading stories about Leaf fans wanting to fire Ron Wilson, some are jumping all over GM Brian Burke calling him a failure and some are even pointing out that this is just more of the same old thing that has been happening in Toronto the past 40 seasons.  I have even witnessed people who bemoaned the demotion of Nazem Kadri after last seasons training camp claiming Kadri was ready based on a good pre-season and now bemoaning his promotion 15 or so games into this season as Kadri isn’t ready for the NHL yet.

With this post I am calling on Leaf fans to just chill and give the process a chance.  I understand your dismay at how the Leafs have played the past 10 or so games, but show a little patience that you always claimed you had and if you are honest with yourselves you will realize that there is real progress here regardless of record.  This is not the same team as last year and in fact it is vastly different, and for the better.  Here are some things we need to remember.

1. This is a very young team, especially at forward.  Kessel, Bozak, Kulemin, Caputi, Kadri, and Versteeg are all age 24 and younger and with youth you will experience ups and downs as they develop.  They need time to develop and we need to be patient with them.  Players don’t become reliable veterans overnight.
2. The goaltending, while still not great, is improved and as a result the Leafs have been in almost every game they have played this season and few losses can be directly blamed on the goaltending.  That’s a far cry from the past couple seasons when you can pretty much turn the game off after one period for a significant portion of the games largely due to horrific goaltending.  Plus their prospect goalies look promising as well.
3. The defense has actually been pretty good.  They are among the league leaders in fewest shots against and combined with their decent goaltending they are middle of the pact in goals against average.  That is a huge improvement from one year ago.
4. Most importantly we need to remember that this is still not the team Burke wants.  He isn’t finished the rebuild yet, especially the forwards. Specifically, he is looking for at least one, maybe two, offensive forwards, preferably with size, for the top 2 lines.  There may be other changes he needs to make as well as even the best laid plans need to be tweaked from time to time.  We need to give him some more time to finish the job.

I understand the concern about the team and its fortunes.  I share that concern.  I don’t like watching the team lost and I certainly don’t know how Burke’s plan will continue to unfold.  Truth is, Brian Burke feels the same and doesn’t know either.  Maybe Bozak and Kadri never develop into useful NHLers.  Maybe Burke can never find another dominant offensive forward to go with Kessel.  Maybe Gustavsson, Rynnas, etc. never develop into reliable NHL goalies and the Leafs continue to flounder with sub-par goaltending.  I don’t know how it will all unfold, but we need to at least give Burke some time to finish his rebuild and then we can evaluate him fairly.