Ryan Whitney and PDO

Ryan Whitney’s spectacular plus/minus on a spectacularly bad team has garnered a lot of attention, even from people who don’t generally believe in plus/minus. I’ve quoted myself above, but the numbers has shown up in the columns of most of the local papers – from the Sun to the Journal.

Is it important, or is it a mirage?

Before we consider that question, I’d like to talk about a statistic tracked at Behind the Net called PDO. PDO is very simple: it is simply the addition of on-ice save percentage and on-ice shooting percentage (please note the difference here between shooting percentage and on-ice shooting percentage; the former is the shooting percentage of a single player, while the latter is the shooting percentage of that player and all of his teammates while he is on the ice). The idea is simple: since on-ice percentages are affected by teammates and opponents and fluctuate wildly from year-to-year, a player with a high PDO is likely to see that number drop, while a player with a low PDO is likely to see it improve.

We’ve already seen one example of that – the difference between Shawn Horcoff in 2009-10 and 2010-11. In 2009-10, he had awful on-ice percentages; this season the numbers have been much better. The impact on his plus/minus (and the positive/negative press he has received at least partially as a result) has been undeniable.

What does this have to do with Ryan Whitney? It turns out that Whitney has a very high PDO, compared to the rest of the Oilers defence (all numbers from 5-on-5 play, and courtesy of Behind the Net):

Ryan Whitney is leaps and bounds ahead of the pack in terms of on-ice percentages. The team was not only far more likely to score on any shot they took while Whitney was on the ice, but they were also far more likely to save any shot against while Ryan Whitney was on the ice.

The question then, is this: was Whitney somehow responsible for those incredible percentages, or was he simply getting the bounces? Obviously it would be preferable if he was somehow causing it, although given the number of other players on the ice that seems extremely unlikely.

However, if Whitney were somehow making his goaltenders better through defensive positioning and his shooters better through pinpoint passing, it should be something he’s done previously for his other teams. How has Whitney’s PDO compared to his defensive comrades historically?

Despite generally playing with offensive players and not facing top opponents, Whitney’s on-ice percentages have never been especially high in comparison to his teammates. In fact, over the past three seasons, his on-ice save percentage has never been better than this season: it has alternated between a very low 0.904 and a decent 0.917. It’s never been close to the 0.935 behind him this season. Whitney’s on-ice shooting percentage has been above the NHL average, ranging from 8.80 to 11.21 (during his time with the Penguins, who led the league in shooting percentage that year). Again, it’s never been as good as the 12.50 number Whitney’s been on the ice for this season.

If historical trends repeat themselves, both Whitney’s on-ice save and shooting percentage numbers will drop off sharply next season. Whitney’s plus/minus, which is a function of the percentages and shots for/against, will also plunge. The alternative is to believe the 28-year old suddenly developed an ability to sharply influence the percentages of others in his seventh professional season.