The stat PDO is hockey’s best indicator of a team’s relative “luck.” PDO is simply a calculation of offensive shot percentage plus team save percentage. In theory, those numbers should add up to 100%, anything above and the team is getting lucky, anything below and they’re unlucky.
The term luck can be heavily debated, and I tend to land more so on the side of saying luck is an excuse more than an explanation of what’s going wrong with a hockey team. That being said though, sometimes the numbers are so astounding that they cannot be ignored. That’s the case 12 games into the 2018-19 season for the Vegas Golden Knights.
Their shooting percentage is 6.34%, last in the league, and their save percentage is 88.78%, 24th in the league. Add them up and you get a PDO of 0.951, tied for 31st in the NHL. It gets even worse if you drop special teams and look only at even strength. Then the Golden Knights PDO is 0.942, far and away the worst in the league.
So what does this mean? Well, for starters, it means based on the number of shots taken and number of shots saved, the Golden Knights are between 14 and 20 goals short of a 1.00 (average) PDO. That’s well over one extra goal per game.
For you math nerds, the Golden Knights PDO is 2.27 standard deviations from the league average after 12 games. For those who have no clue what the heck that means, historically, teams one standard deviation away from the average are considered unlucky. Teams two standard deviations from the norm are considered extremely unlucky. The Golden Knights are 2.27 away, so they are pushing some sort of voodoo magic level of bad luck.
Of course, a 7-0 game here or there could completely swing that number back without seeing a massive impact in the standings, but if it’s a slow burn back to the 1.00 number, or anything close, we’re literally talking about a goal a game difference.
There are many reasons to explain it and there’s no question a portion of the numbers rest on the shoulders of poor play by the Golden Knights. However, there’s a difference between a couple of missed opportunities and a couple of breakdowns and a 0.951 PDO.
Since 2007-08, no team has finished with a PDO of less than 0.966. If the Golden Knights were sitting at that number right now, they’d have about five more goals. The worst shooting percentage over that span is 6.9%. Vegas’ is currently 6.34%. If they had that extra roughly 0.5% back, they’d have another three goals. And these are comparisons against the worst teams in 10 years!
However you want to slice it, the fact of the matter is the Golden Knights will not finish the season with a PDO anywhere close to what they currently have now. When it comes to shooting percentage and save percentage, things will change and in a big way. That’s not a prediction, that’s a statistical fact. (Well, as long as you don’t believe the 2018-19 Golden Knights are the one in a 34 billion to 1 situation.)
**Stick tap to our good friend Marissa (@Taxpro4gamblers) for helping with the in-depth mathematical analysis used in this article.**