There is an old-school way of thinking that says heart and character drives runs in hockey (it doesn’t). It says that a team comes together and through some pesky determination (luck) the team wills themselves to win.
The problem with that line of thinking is that every team wants to win, and if you could simply will yourself to victory then nobody would lose. Instead hockey focuses around two main ideas: how often can you put the puck in the opponents net, and how often can you keep it out of your own. We know these ideas as save-percentage, and shooting percentage.
So if it’s not an impressive work ethic that drives these runs, what is it? Typically it’s a fluctuation in one of the two afore mentioned stats. A team will suddenly start finding the back of the net more, or their goalie will suddenly be making more saves than usual. The runs can last for days, weeks, even months, but at the end of the day they will end (See Maple Leafs, Toronto).
The trick then is to discover when these runs occur, what is driving them, and what we can expect to happen in the future. Enter PDO. The acronym doesn’t stand for anything but the Maple Leafs executives dubbed it Percentage Driven Outcomes after being explained the concept by Assistant GM Kyle Dubas. It’s a name I like because it accurately reflects what it is PDO measures.
How often are the outcomes we are witnessing on the ice an effect of an unsustainable percentage? There are numerous cases that can be pointed to this year, most recently the startling play of Senators goalie Andrew Hammond. The career AHLer is now 7-0-1 as a starter in the NHL, has a .943 sv%, and a 1.54 GAA. The numbers top the NHL; and they come from man who posted a .904 sv% in the AHL.
Here’s where it gets trickier. These runs occur all the time, not only in the NHL, but across all sports, and are nearly impossible to predict. They’re part of the reason why people love sports. They are also influenced by random chance, we may not know what has caused a player or team to suddenly get the bounces. It could be a subconscious focus, an event they can rally around, or simply blind luck. Understanding the psyche of sports is something that we see GM’s and pundits try to do all the time, and more often than not, they fail.
So if we don’t know when these runs will happen, or why they happen, what’s the point in paying attention to PDO? Why not simply enjoy the sport for what it is? In a word, confidence. PDO gives fans confidence that their losing struggles may not last forever. The Maple Leafs will eventually score under Peter Horachek, Andrew Hammond will eventually let in a goal, and the Flames will fall back to earth.