By JASON LOWENTHAL
Today we conclude our series on advanced analytics in hockey
by putting it all together. Remember back in our first piece when we introduced
Corsi and Fenwick? Let’s go back to that.
Corsi = shots on goal + blocked shots + missed shots
Fenwick = shots on
goal + missed shots
Generally, Fenwick is considered to be a more accurate
indicator, so we’ll stick with that as our baseline possession metric. The
reason is because Fenwick does not include blocked shots in the equation
because it considers blocking shots a skill, whereas Corsi does not.
Fenwick is used as a way to expand possession statistics in
hockey because calculating time of possession is incredibly difficult. A team
can’t have 20 different guys watching each of the 20 players that dress every
game. That costs time and money. So, we use Fenwick instead. Here’s an example
of Fenwick using Jonathan Toews during five-on-five play.
iFenwick (Toews) = shots on goal + missed shots
iFenwick (Toews) = 141 shots + 33 missed shots
iFenwick (Toews) = 174
(iFenwick stands for
Individual Fenwick)
Now that we have Fenwick down, we can take a look at Fenwick
For percentage. FF% can be used both individually and for a team, and is
probably the best metric that advanced analytics has to show its validity. FF%
is calculated by using the following formula:
FF% = (100 x Fenwick For) / (Fenwick For + Fenwick Against)
Essentially, FF% is used to measure the percentage of shots
a team has in a game to show possession. Here was the FF% for the Chicago
Blackhawks last season:
FF% (Blackhawks) = (100 x FF) / (FF + FA)
FF% (Blackhawks) = (100 x 1565) / (1565 + 1285)
FF% (Blackhawks) = 156,500 / 2850
FF% (Blackhawks) = 54.91
This means that during all of their games last season, the
Blackhawks had 54.91 percent of the shots (on goal and missed).
The table below shows the top ten teams from last season in
the NHL for FF%:
Los Angeles
Kings
|
56.1%
|
Chicago
Blackhawks
|
55.4%
|
San Jose Sharks
|
54.6%
|
St. Louis Blues
|
53.7%
|
New Jersey Devils
|
53.6%
|
Boston Bruins
|
53.4%
|
New York
Rangers
|
52.6%
|
Vancouver Canucks
|
51.6%
|
Detroit Red
Wings
|
51.5%
|
Tampa Bay
Lightning
|
51.3%
|
Green indicates team made playoffs
Red indicates team missed playoffs
As you can see, eight of the top ten teams in terms of FF%
ended up making the playoffs last season. This gives significant validity to
FF% to the use of advanced statistics in hockey in general.
Unfortunately, given the limited budget of USHL teams,
advanced analytics are hard to come by in the league. However, as one can see
from this four-part series, it can be done.
Advanced statistics are a good way for guys doing the little
things to be recognized. However, it will never surpass the eye test. Although
more and more teams are moving towards the whole “Moneypuck” idea, a
combination of the two theories is best, because both have imperfections.
Advanced stats worked for Billy Beane and the Oakland A’s, time will only tell
if the same will work in hockey.