## Wednesday, 10 September 2014

### NHL and Advanced Statistics ( Corsi-Number)

The NHL has developed in many ways over the past ten or so seasons.  We have seen rule changes, lockout seasons, and even several unfortunate events which resulted in the loss of some great individuals.  However, one thing that has not changed is the importance of numbers and statistics.

We have come so far from the days where the only stat that counted was a teams' record.  In modern day hockey, we have seen an incredible revolution in hockey statistics.  The value and application of these stats have proven crucial to the game.  When it comes down to it, even hockey is a game of averages and percentages.  If utilized correctly, a team can theoretically maximize their chances of winning.  Of course these systems are far from perfect, but they have proven to be crucial in analyzing an individual's value.  For example; baseball is undoubtedly a game of numbers. Going late into the game, a manager will occasionally change out a pitcher for just one batter.  Sometimes you will hear people questioning the move, and wondering why he would make that change.  The answer is simple, that batter is statistically less likely to get a hit off certain pitchers.  I did some research to prove this point and I found that Ted Williams hit only 12% of his home runs off of left handed pitchers.  Babe Ruth hit only 30%, and Duke Snider hit a measly 8%.  When given those numbers, it seems stupid to NOT make that change.

The same exact thing happens in hockey, except slightly less focus is placed on match ups.  Do not get me wrong, match-ups are key.  However, most of these modern hockey statistics are used to identify hidden information which can help to understand why a team is performing a certain way. I guess it would make sense to use the most talked about modern statistic, the Corsi-Number.

Essentially, each individual player receives a score based on their even-strength play.  This score is very similar to a plus / minus rating, except the score itself is determined by how many shots are directed at the net while that player is on the ice.  This includes shots on net, missed shots, and blocked shots.  Any shot that is directed at one's own net is a minus, and any shots directed at the opponent is of course, a plus.  If you are still somewhat new to the stat, various websites will provide some great info for you.

What stats like this do is break down the game into a very organized set of numbers.  Each and every player earns these statistics, and it helps coaches as well as General Managers make important decisions.  On a very basic level, it is obvious that teams who get more shots win more games.  It is a very basic law of averages, but it can be over-looked.  What the Corsi number does is analyse the score of each individual on the team.  All a coach has to do is take that number, and locate which guys are struggling the most.  Most good coaches will make some slight adjustments to get the team average up.  All of a sudden, each line is maximizing shots for and drastically reducing shots against ( in theory ).

I was scanning through some of the Corsi stats online and it can be a real pain to find.  However, the hockeyanalysis.com website does have a variety of different versions of the classic Corsi-number.  From what I have seen, certain teams have a lot of individuals making the list compared to others.  For example, the LA Kings slaughtered the competition with regards to Corsi and other related statistics.  Over the past two seasons, the Kings have ten players who made the top 100 list for Corsi ratings.  This includes depth players like Jake Muzzin, Dwight King, and Roby Regehr.  I almost expected Kopitar, Doughty and other top tier players to make the cut, but seeing a lot of depth guys is quite surprising.  None of these individuals are known for shooting the puck.  In fact, many of them are role players who focus primarily on making the smart play and limiting time in the defensive zone.  Nonetheless, these stats are vitally important for the Kings coaching staff as they plan to maintain the same level of success moving forward.