Stat Hack: Is David Rittich a Calgary Flame Weakness?

February 11th, 2019 | Posted in Commentary | By: D'Arcy McGrath

It’s become the topic of day in Calgary, at least in hockey circles since the team came back from an extended break in and around the National Hockey League’s NHL all star game.

David Rittich was pulled early in a loss to the San Jose Sharks on Thursday night, and then was out foiled by his counterpart Jacob Markstom in a loss on Saturday night despite the Flames having a 47-25 shots on goal advantage. The Flames are deep, offensively gifted and ready for what could be a deep playoff run, but is their Achilles Heel their goaltender?

The Season Numbers

Assessing goaltending stats takes a lot of filtering. You can’t include every goaltender or you run the risk of several top ten goaltenders by measure of save percentage having less than a full game of work, skewing the data terribly. With that the first order of business is to knock the pack down to 62 (one starter and one backup per team effectively) and have a look at the numbers and then have a look at the situational detail.

David Rittich in simple terms is ranked the 18th best goaltender of those that have played 600 minutes this season in any situation (63 stoppers). That’s not elite but it’s not terrible either … a middling goaltender with a .915 save percentage. At even strength he moves up a few spots to 15th with a .930 save percentage in all even up situations. At five on five he’s 11th with a .936 save percentage, delivering a result just outside the top ten.

In 2019 we have better numbers however to measure goaltenders, and two metrics have been introduced in the last several years to even out the play of the team in front of the goaltenders with an eye to comparing each stopper against what an average goaltender would do in the nightly situations they face. These measures come in the form of dSV% (which is the differential between actual save percentage and expected save percentage), and Goals Saved Above Average (GSAA), which takes the same results and alters them into a total goals differential between each stopper and the average performance.

dSV% GSAA Rank
All Situations 0.29 2.50 25 / 25
Even Strength 1.18 8.18 7 / 8
Five on Five 1.60 10.72 7 / 3

When you take into account what the Flames give up his numbers improve dramatically, as he’s top ten in five on five and even strength for both metrics while having trouble when down a man; a stat that likely has a lot to do with his teammates penalty killing ability as well.

When teams are playing without an advantage, David Rittich has been money this season, but is that skewed based on his early success? Or is he still getting the job done?

Segment by Segment

His numbers suggest he’s had a solid season, but has he slid of late?

There’s always been debate about how he handled the workload last season when Mike Smith went down, with many suggesting he collapsed when the numbers suggest he had a spotty game or three but not the biblical emotional breakdown suggested by many.

This year the Flames had Mike Smith as a starter in October, a tandem in the month of November and December and then Rittich the starter for January and February.

Has his play slid as the focus and pressure of being the man has come to bare?

Set SV% QS% RBS% Wins
1 93.5% 80% 20% 4
2 93.4% 100% 0% 4
3 91.9% 60% 20% 2
4 90.6% 40% 20% 2
5 90.3% 60% 20% 4
6 90.6% 60% 20% 3

The answer is a mixed bag; yes he’s come off, but his results haven’t really changed all that much, or at least to the point that would suggest a concern.

Each segment above represents five starts, and he’s now started 30 games on the season. His first two segments had out of this world save percentage totals, near perfection in the category of quality starts, and four victories. Only one of the first ten starts categorized as a “really bad start” as per the definition (sub .850 save percentage).

The next two segments had a slide in terms of save percentage, and only two wins apiece as Rittich settled into an average starter role instead of the Herculean backup he was in the first two sets.

Segment five has a small slide in save percentage again, but a bump up in quality starts and wins.

Finally the most recent five game set has a bounce back in save percentage, a solid quality start index, and three wins in five starts which includes a yank against the Sharks. His play in Edmonton and in two games against the Hurricanes was more than solid.

So what does this all say?

The NHL has likely looked into his tendencies and have solved him to some degree since the first two data points (segment two ended on November 23rd). Since then Rittich hasn’t been the top five goaltender that he was to start the season, but has been consistent in besting the league median (.902) and providing the team with a top 10-15 goaltender as the season grinds toward the final quarter.

Where he goes from here speaks to his ability to shore up his weaknesses and get back to his early season prowess, or at every least halt the slide and maintain the upper half goaltending statistics he’s posted.

Is that enough for a deep drive in the playoffs? With better team defense it certainly could be, and given the availability and cost of an upgrade it’s clearly the direction the team will go. Hints of a backup upgrade make sense if you fear injury, but Rittich an above average starter whether you look at the season as a whole, or his play recently.

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