Puck possession seems like a pretty simple concept on its face. Having the puck more than your opponent sounds like a good plan and I doubt you need me to provide you with a bunch of numbers to convince you of that. As we look deeper into puck possession, we see that there is a difference between having the puck for a long time and meaningful puck possession. Your team may spend a lot of time in the offensive zone passing the puck around the perimeter in order to set up a “perfect shot” as if they were on the power play. In terms of time of possession, this may register as a positive; however, meaningful puck possession consists of two main elements: shot generation and shot suppression.
Frankly, it’s unfortunate that we have tried so hard for so long to split hockey into offense and defense. This kind of thinking has led to a view that offense happens in the offensive zone and defense happens in the defensive zone. For years, hockey analysis approached the game as if offense and defense somehow existed independently of one another. The reality is that forwards and defensemen are equally important to all aspects of the game. My point is that our approach to analyzing hockey is often backwards.
Hockey is an incredibly fluid game that does not lend itself well to a rigid, two sided understanding of “Offense” and “Defense”. In hockey, offense and defense or, to more aptly name them, shot generation and shot suppression, are active at all times in all zones.
When a team has poor shot generation stats, the forwards usually get the blame. When a team gives up too many shots, the defense usually gets the blame. The issue with this is that shot generation problems frequently start with the defensemen and the defensive zone structure used by the coach. Likewise, shot suppression problems often start with the forwards, defensemen and offensive zone structure used by the coach.
Our dichotomous approach to hockey has led to conservative thinking and systems. Conservative defensive systems instill a mindset that, the moment the puck enters the defensive zone, results in “don’t give up a goal” and “make the safe play” thinking when it often should be “get the puck so I can spring the forwards up the ice”. Even splitting hockey into shot suppression and generation is difficult to do because they overlap so much. In order to do some analysis, we have to start somewhere, so these terms are probably the best because they are more inclusive of the entire ice surface.
When you add shot generation and shot suppression together, the result is the pace of the game. While CF% (All shot attempts for %) and similar measures tell us the percentage of shots a team has for it, it does not reveal the pace of the game. For example, Dallas has the highest Score Adjusted CP60 (Corsi Pace Per 60) in the NHL through 79 games at 110.0. The Stars CF% is 52.7%. When we break down shots for and against, we see that the Stars CF60 (Corsi For per 60) is 57.9 and CA60 (Corsi Against per 60) is 52.0. Colorado is not far behind the Stars in terms of game shot pace with a CP60 of 108.2; however, the Avs CF60 is 47.8 and CA60 is 60.4. The Avs CF% of 44.2 is similar to New Jersey’s 45.7 CF% but the Devils CF60 of 43.0 and CA60 of 51.1 results in a pace of 94.1, which is the lowest in the league. *These numbers are from publicly available data current through 80 games of the 2015-16 regular season on http://www.war-on-ice.com
So what explains these big differences in game shot pace both for and against the teams? We’ve seen that a team that is good at generating shots may not be good at suppressing shots. If we don’t understand game pace, this seems almost illogical. The common wisdom behind puck possession says that if my team has the puck more (generating shots) then their opponent will not have the puck as much and thus not be able to generate shots. Why isn’t this true? Why are some teams great at generating shots and yet still give up a lot of shots against? Are teams with good shot generation numbers really just “gaming Corsi” as some have suggested?
We can’t answer these questions unless we know how teams generate shots and suppress shots, and this is also where we need to make some adjustments to the way we think about hockey. Regardless of whether we are talking about generating or suppressing shots, good hockey teams have two critically important habits in common: Controlled Zone Exits and Puck Recovery.
Because this is a fairly dense subject, I’ll break this up into several posts to ease digestion.
- Shot Generation and Controlled Zone Exits
- Shot Generation and Puck Recovery
- Shot Generation and Game Flow
- Shot Generation and the Neutral Zone
- Shot Suppression and Controlled Zone Exits
- Shot Suppression and Puck Recovery
- Zone Time & Goals
There may be a few more on this subject depending upon how these shake out. I’ll add links here for each post as it goes up.