Advanced Stats Paint Bleak Picture for the Toronto Maple Leafs

Mike DenrocheContributor IIIJuly 28, 2013

Disappointment could be in store for the Leafs and their fans next season
Disappointment could be in store for the Leafs and their fans next seasonAbelimages/Getty Images

After finishing fifth in their conference, making the playoffs and putting up a strong fight against the eventual Eastern Conference champions in 2012-13, the Toronto Maple Leafs enjoyed what many fans considered a promising season in what was only the beginning of something great.

On the surface, it's easy to see why there’s plenty of optimism in Toronto. Dig a little deeper into the realm of advanced stats, however, and a different story presents itself.


Corsi and Fenwick

What Is It?

Perhaps the most commonly used and most familiar advanced stats to the average fan are Corsi and Fenwick. In case you were wondering, the words Fenwick and Corsi mean nothing statistically nor do they mean anything athletically—they're simply named after their respective founders.

Both Corsi and Fenwick are used to measure puck possession. Where they differ is how they're calculated: Fenwick combines shots on net and shots attempted, while the more commonly used Corsi combines shots on net, shots attempted and blocked shots.

The most effective way to analyze a team's ability to control the flow of the game is calculating a team's Corsi For or Fenwick For percentage (CF% or FF%). 

A team's CF percentage is essentially its share of puck possession time during the game. It's calculated by dividing the number Corsi events that a team produces by the number of Corsi events allowed and produced, expressed in a percentage. FF% is calculated the same way.

A CF percentage or FF percentage above 50 percent indicates a team controlled the flow of the game more often than not, while anything below 50 percent indicates the opposite.

The main criticism of Corsi and Fenwick is that all shot attempts are valued equally when, in reality, a hard snap shot from the slot is more likely to produce a goal than a weak wrist shot from the point that misses the net.

That may be true, but according to a fascinating piece by, it doesn't seem to matter.


How Did the Leafs Perform in Terms of CF% and FF% Last Year?

The Leafs posted the worst CF percentage (44.1 percent) and FF percentage (44.0 percent) during five-on-five play this past season

In fact, the Leafs were in the bottom six in the league in CF percentage in almost every other situation including power play (25th), penalty kill (26th), five-on-five in close games (29th), five-on-five when leading (28th) and five-on-five when trailing (25th).


What Does That Mean?

The Buds were terrible at maintaining puck possession last season.


Is There Cause for Concern?


Corsi and Fenwick have proven to be great indicators of future team success. To illustrate this point, consider a couple of beautiful graphics, courtesy of Chris Baker over at SB Nation, that show how playoff and non-playoff teams from 2008 to 2012 fared in terms of FF percentage.

As the graphics show, the vast majority of playoff teams from 2008 to 2012 had a FF percentage above 50 percent, and no team made the playoffs with a FF percentage below 45 percent, making the 2013 Leafs the first (and only) team to do so in the last five years.

Fenwick and Corsi, like most statistics, rely on sample size. There will always be teams—like the 2013 Leafs—that make it into the playoffs simply because the regular season ended before their fortunes turned, but it's clearly not a recipe for long-term success.



What Is It?

PDO is an excellent statistic for determining luck. PDO is simply calculated by adding a team's shooting percentage and save percentage together.

In order to accept what PDO tells us, it's important to understand that shooting percentage and save percentage numbers are heavily based on luck. Even the best scorers and top goalies experience peaks and valleys year to year in these two statistics. 

The end result of a shot on goal can either be a save or a goal, meaning the relationship between shooting percentage and save percentage is a zero sum game—if one goes up, the other necessarily goes down by the same amount. As such, the mean PDO is 1.000. If a team has a PDO above 1.000, it's considered fortunate, and vice versa. Teams that benefit from good luck (or suffer from bad luck) one year are likely to regress to the mean of 1.000 the next.


How Did the Leafs Perform in Terms of PDO Last Year?

The Leafs ranked first in the league during 5-on-5 play with a PDO of 1.030.


What Does That Mean?

They rode an unsustainable shooting percentage en route to being the luckiest team in the league.


Is There Cause for Concern?

When you consider the addition of Jonathan Bernier, and the fact that the Leafs are bringing back essentially the same defense corps from last season, the Leafs' 15th ranked five-on-five save percentage of .924 appears to be sustainable.

That's the good news.

The bad news, of course, is if the Leafs regress towards the mean PDO of 1.000, their league-leading five-on-five shooting percentage of .106 could tumble about three percent.

It doesn't sound like much, but based on the Leafs' 2012-13 shots on net and Pythagorean expectation, a three percent drop in shooting percentage would have cost the Leafs 29 goals for and their playoff spot.


Zone Starts

What Is It?

Zone Starts is simply the percentage of faceoffs a team takes in each zone.

Zone Starts, like Fenwick and Corsi, is a metric of puck possession. The logic behind Zone Starts is the assumption that if a team is controlling the play, the majority of the stoppages (and therefore the majority of the faceoffs) will be happening in the offensive zone.


How Did the Leafs Perform in Terms of Zone Starts Last Year?

During five-on-five play, the Leafs had the lowest Offensive Zone Faceoff Percentage (OZFO%) in the league at 26.8 percent and the second highest Defensive Zone Faceoff Percentage (DZFO%) in the league at 35.6 percent.


What Does That Mean?

The Leafs were taking a lot more defensive zone faceoffs than offensive zone faceoffs, giving further credence to the notion that the Leafs were consistently outplayed in 2012-13.


Is There Cause for Concern?

Defensive zone faceoffs are never good. Regardless of how good a team is on the draws—an area where the Leafs are exactly average—defensive zone faceoffs almost always lead to a scoring chance for the opponent.

According to stats wiz Gabriel Desjardins, even after winning a defensive zone draw, the average team surrenders 0.244 shots in the first 30 seconds following the drop of the puck. The consequence of losing a defensive zone faceoff is even worse, with the number of shots doubling to 0.489 shots in those initial 30 seconds after the draw.

To illustrate this point, consider the chart below:

Using 2012-13 data prorated for an 82-game season, with all things being equal, the Leafs would have allowed 12 more goals than the top DZFO percentage team in the league—worth approximately two wins over a full season according to Pythagorean expectation.

It's also important to note that while the Leafs are taking draws in their end, their opponents are not. Zone Starts is a double-edged sword—having a poor DZFO percentage not only makes a team more susceptible to allowing goals, but it also hurts that team's chances of creating offense.


Looking Ahead to Next Season

It’s important to remember that advanced stats, like traditional stats, are not the end-all be-all. Advanced stats do, however, provide us with a new way of analyzing the game, a broader understanding of what leads to victories and an ability to quantify it. They may not be the end-all be-all, but the information they provide shouldn't be ignored.

Because the Leafs are such a young team, it's difficult to determine how much of the ugliness uncovered by advanced stats will improve next season, simply through learning and development. The acquisition of a good puck possession player in David Clarkson was also a step in the right direction.

But expectations should be tempered, Leafs Nation. This team still has a ways to go.