From the speed of play to the shape of the puck to the simple fact that the game is played on an unnaturally slippery surface, the nature of the sport of hockey lends itself to see outcomes determined by a fair amount of luck.
For years the stat nerds have tried to quantify the term “puck luck.” The idea is that once we identify what it looks like to be lucky, we can reasonably use the laws of variance to predict when a team will come back down to normal.
Baseball has been using these methods for decades. As the sport at the forefront of keeping and relying upon stats, it’s always been easy to see when a player is hitting .750 for a week, he’s probably going to regress in the near future.
That same idea is where our geeky friends came up with the term PDO. Like all good hockey stats, the name doesn’t make any sense. It literally doesn’t stand for anything as it was just a nickname of a blogger back in the early 2000’s. The stat is basically a measurement of puck luck as it adds shooting percentage and save percentage. The idea is that every shot results in a save or a goal, when you add them up for all teams the league average will always be 100%. So, a team or player with a PDO above 100 is lucky and expected to regress while a number under 100 is unlucky and expected to get better.
Why do I tell you all of this? Well, because the Golden Knights have been on an incredible run of fortunate PDO to start the season. They currently sit at 104.3 at 5-on-5 which is 2nd in the league behind the Vancouver Canucks (108.8). That means regression is coming. Right?
Hold on a second.
In the playoffs last season the Golden Knights won 16 of 22 games en route to winning the Stanley Cup and never faced an elimination game. They did it with an incredibly lucky PDO of 106.5.
Last year, after the All Star break, those same Golden Knights went 22-4-5 to win the Pacific Division and clinch the #1 seed in the Western Conference. They did it with an incredibly lucky PDO of 104.1.
Let’s recap. 104.3 this year. 106.5 in the playoffs. 104.1 in the latter half of the season last year. Some (most) would say this is unsustainably lucky and the team is in for a major regression in the near future. I’m a little more skeptical of that and have been beginning to wonder if maybe this is a trend more so than a blip.
Admittedly, I’m a believer in PDO for the most part. The current Vancouver Canucks, yeah, I think they’re going to regress big time. So typically, I’d see the numbers for Vegas and think the same. But, the numbers have stayed in the “unsustainably lucky” category for far too long to keep fitting this team into the same box as everyone else.
So, I set out on a mission to figure out why, or maybe how, the Golden Knights are doing this, and more importantly, if it’s sustainable.
After digging into the numbers in all sorts of different ways, the first part of the explanation as to how the Golden Knights have maintained a strong PDO is the location of the shots they take compared to the ones they allow.
Let’s start by looking at this year’s numbers. On the season, the Golden Knights have taken 269 shots on goal while allowing 306. Here’s where they’ve come from.
Low-Danger (1.8% league average shooting percentage)
Medium-Danger (8.5% league average shooting percentage)
High-Danger (17.5% league average shooting percentage)
43% of VGK’s shots have come from low-danger positions on the ice while that number is 50% for their opponents. The Golden Knights are basically right at the league average on how many they take, while they allow 25% more than the league average to their opponents.
Those numbers are similar in the playoffs last year and since the All Star break of the 2022-23 season. In the postseason, the Golden Knights had the 3rd fewest low-danger shots while allowing the 2nd most. Since the break, they were bottom 10 in shots taken and top 10 in shots allowed. Medium and high-danger shots remained about the same for and against.
These numbers inflate save percentage while not impacting shooting percentage, giving the Golden Knights a built-in bump to PDO.
This is absolutely sustainable because of the man behind the VGK bench. The way Bruce Cassidy asks his team to play, these numbers are expected to remain at a similar ratio, meaning we can always expect a higher save percentage.
The second portion of the explanation to VGK’s incredible PDO run is their finishing on medium and especially high-danger chances. Simply put, it’s astounding.
This season – 102.9 (9th)
2023 Postseason – 116.7 (1st)
Since All Star – 107.3 (1st)
This season – 106.7 (3rd)
2023 Postseason – 108.0 (1st)
Since All Star – 105.2 (3rd)
Remember, PDO is measured against 100. Even a few points over 100 is considered lucky. Four of the six numbers above are over 106.
The league average shooting percentage at medium-danger is 8.5%, the Golden Knights over the three samples are 15.3%, 13.0%, and 12.4%. The high-danger numbers are similar. League average at high-danger is 17.5%, VGK’s are 28.5%, 21.9%, and 17.5%.
For the past 66 games, the Golden Knights have finished well above league average on high-danger shots.
This is the part that is somewhat unexplainable, especially in last year’s playoffs.
William Karlsson, who has averaged about an 11% finishing rate on high-danger chances scored 7 goals on 15 shots in the postseason. That’s a 47% shooting percentage, almost triple the league average, and more than four times his personal average.
Ivan Barbashev shot 35% on high-danger chances while his average is below 10%. Mark Stone posted a 30% rate in the playoffs with about a 20% average in his career, and Jonathan Marchessault 29% with around a 22% personal average.
This is where regression is likely. The Golden Knights generate about the same number of medium and high-danger shots as they allow, they are just massively outperforming their opponents in them.
The system certainly has something to do with it, especially defensively as Vegas has built their D-Zone coverage around protecting the center of the ice. Even if teams get into those areas the shots are almost always challenged. On the other side of the ice, the Golden Knights definitely prefer quality over quantity and are often criticized for overpassing. They typically have a player in front of the goal attempting to clean up rebounds and they wait until they have a decent shooting lane to unleash the shot.
Sure, it can account for some of the overperformance, as can the generally high talent level of the VGK roster, but probably not to the tune of a PDO over 106.
All in all, the Golden Knights’ run of tremendous PDO probably isn’t here to stay forever, but it also shouldn’t be expected to crash back down to earth in a hurry. The long-distance shot bump will always be there as long as Bruce Cassidy remains behind the bench. The question is whether or not they can continue outshooting their opponents from in tight at the rate they have over the last eight months.
Having spent way too much time researching this, I think it’s reasonable to say PDO remains a useable stat when examining the Vegas Golden Knights’ “luck.” I’d just say where we use 100 as the base measurement for most teams, it’s probably closer to 101 or 102 for the reigning Stanley Cup champions.