Silver Nuggets: The Ottawa Senators and Shot Quality

They [the Ottawa Senators] are giving up a lot of shots, but sometimes a lot of shots, if they’re not inside, don’t mean a lot anyways.

- Lindy Ruff, coach of the Dallas Stars (via NHL.com)

As we all know, the Senators have had an awful season in terms of preventing shots. They currently allow a league-worst 34.1 shots per game, 1.3 more than the second-last Flyers, while only taking 28.7 shots per game, good enough for 22nd. That -5.4 shot differential per game is the league-worst by 1.7 shots. Typically, allowing five more shots per game than you take isn't a recipe for success. The shot attempt statistics show a similar picture: Ottawa is 28th in 5v5 Corsi (46.36%) and in 5v5 Fenwick (46.32%), both from Natural Stat Trick.

Now an interesting thing happens when you account for event, score, and venue, a technique explained by Puck on Net. Ottawa rises to 21st in the league in even-strength Corsi (48.5%) and Fenwick (48.6%). Ottawa's rise isn't nearly as good when just adjusting for score and venue, so it looks like for Ottawa, the event is skewing things. But that's an article for another day.

Back to the idea at hand: Ottawa is getting badly outshot. The Lindy Ruff quote at the top has some merit, in that not all shots are created equal. Many have said that shot quality matters less as the sample size gets bigger, but others have tried to find a way to account for it. To Ruff's credit, he didn't actually say that Ottawa takes a lot of shots from the perimeter, just that they might which would then skew the stats. However, it's been used a few times as proof that Ottawa keeps shots to the perimeter. It's been brought up a couple times in the comments, but I wanted to take more space in an article to examine if Ottawa actually does a better job of keeping teams to the outside. Spoiler alert: they don't.

All graphs use War on Ice's Hextally feature. This first one shows Ottawa's shots-allowed rates relative to other teams in the league:

The data is split into three zones. The colour of the circles shows the statistical significance, so the darker red is more significant, while the bold number shows the relative rate compared to the rest of the league from the given zone. What's immediately clear is that Ottawa allows more than the league-average number of shots from each of the three zones calculated (called low-, medium-, and high-danger from now on). Ottawa may allow proportionally more shots from the point and perimeter (low-danger) than the average NHL team, but still allows more from every region than the average NHL team. Allowing 10% more medium-danger shots and 6% more high-danger shots than the average team is still a problem over the course of a full season.

This second graph shows the shooting percentages of teams against Ottawa relative to the league average:

And this graph explains a lot. Ottawa's goalies have been 25% better than the rest of the league at stopping shots from the high-danger areas. Since shooting percentages from the high-danger area are typically much higher than even the medium-danger area (two-and-a-half times more likely to score, based on stats so far this season), this accounts for a huge number of Ottawa's wins this season. Are Ottawa's goalies really 25% better than other goalies in the NHL, or is Ottawa just getting really lucky so far this season? The fact that Ottawa's goalies have been nearly 50% worse from the medium-danger region tells me that they aren't that much better than the league average, they've just been stopping an unsustainable number of pucks from in tight. If you had to pick whether your goalies were better than the average on shots from the crease or the high-slot, you'd probably (rightly) pick the crease. The fact that Ottawa's goalies have been succeeding more there is reflected in the team's position in the standings.

So we've seen that Ottawa allows more shots than the average team in the league from everywhere, but Ottawa's goalies have been much better than the league average at stopping shots from the high-danger area right in front of the net. This on its own isn't a reason for concern. One stat can't ever paint the whole picture. It's just one in a series of arguments that says that this season's Sens aren't really deserving of the wins they've been getting. I'm happy they've been winning, and a lot of the forwards have been playing well, but I'm hoping things get sorted out on the defensive end as the season goes on.

Sens Links:

• The Sens lost to the Coyotes over the weekend despite dominating the possession game [Silver Seven, Rank the Performances]
• The B-Sens lost yet again in what's turning out to be a miserable season for the team [Silver Seven]
• Trevor points out that the Sens' December is against a lot of really good teams [Silver Seven]
• B_T looks ahead to the week's games in Sens Week Ahead [Silver Seven]
• Looking back on the week that was in Ups and Downs [Silver Seven]
• Callum joined Ian Mendes on TSN 1200's Advanced Chats on Sunday. If you weren't up listening to the radio at 9 a.m. on Sunday, you can give the audio a listen here [Silver Seven]
• Nichols with a look at Pierre "PR" Dorion's latest media availability [6th Sens]
• Nichols also looks at PDO, and which lines are due for some heavy regression. The Pageau line in particular has been far worse than down the stretch last year [6th Sens]
• SensChirp with a column of Monday thoughts, talking about Wiercioch and Kostka among other things [SensChirp]
• A FanPost by Be_rad, arguing why he thinks Ottawa's shot disparity is a problem thus far [Silver Seven]
• Peter Levi's most recent thoughts on the most recent Sens, B-Sens, and Icemen games. He also looks at the signing of Darian Dziurzinsky (brother of David) to a PTO, and how that's led to some confusing punishment of Tobias Lindberg [Eye on the Sens]
• Ken Warren talks about how it's Craig Anderson's net right now [Ottawa Citizen]
• Warren also looks at the bargain that Mike Hoffman has been for the team so far [Ottawa Citizen]

Other Links:

• From PPP, a great piece talking about how appeal to authority issues arise from having Mike Babcock coaching in Toronto [Pension Plan Puppets]
• Clare Austin with a great piece looking at the evolution of the butterfly, and how we should refer to it as a tool used by all modern goaltenders, rather than a description of a certain type of goalie [In Goal Mag]
• Sean Gentille runs through some thoughts on the media's recent treatment of Kobe Bryant, Kevin Durant rushing to his defence, and the comparison to Michael Jordan [Sporting News]
  
• Drew Magary's take is far less positive towards Kobe [Deadspin]
• Jack Ries with some work on looking at the importance of takeaways and giveaways. The final verdict: 486 takeaways or 351 giveaways equals one win. [Hockey Prospectus - takeaways, Giveaways]/