Since I went after the JOFA line a few days ago, I’m getting my start here at @OnTheForeCheck by “attacking” what we hold dear. Now it’s Pekka Rinne’s turn. Judging by jersey sales, he’s still pretty popular. Not that I don’t like Rinne. In fact he’s been my favorite goalie in the league for the last decade, but for me, I don’t go through life with the rose-colored glasses on. I’d rather someone shoot me straight.
Goalies Are Voodoo
The Hockey News’ Matt Larkin wrote this spring about why Rinne is the league’s most polarizing goaltender. The eye test crowd loves him, but the data crowd is a but more cautious. The most poignant part about that for me is the discussion of rebound control. I recall Chris Boyle doing some work with rebounds a few years ago. The only place I’ve seen rebounds tracked is Natural Stack Trick but theirs is done by tracking individual skaters, not by goalies. More on that later.
Travis Yost opined two years ago that “Goalies Are Voodoo” and maybe they are. Perhaps GMs realize that too, since only four goalies have gone in the top 50 picks in the draft in the last three years. None higher than Ilya Samsonov to the Capitals at #22 back in 2015. Of the Top-10 goalies in the league last year in Goals Saved Above Average only two were picked higher than 39th. Unlike forwards or defensemen, quality can be found almost anywhere in the draft.
Judging Past Performance
Fortunately for us. Pekka Rinne has a large body of work, logging more than 500 regular season starts tallying over 29,000 minutes along with registering nearly 13,000 saves in his career.
Goalie Heart Rate
One of criticism’s of Rinne’s greatness is that the defense is front of him does such a tremendous job that the work load on Rinne is relatively light. I looked at last year’s data and plotted each goalie with more than 600 minutes in net. I wanted a sample size of goalies who’d have seen the equivalent of 10+ starts. Notice I also used shots against rather than Corsi or Fenwick. In SA/60 Rinne finished the season at 29.49, almost exactly at league average of 29.67.
Rinne is far below the league average on percentage of high danger shots against at just 17.8% compared to a league average of 21.5%. To put this in perspective an average starting goaltender plays about 3,300 minutes. At 29.49 SA/60, Rinne would have faced 1621 shots. Of those shots 288 would be of the high-danger variety. An average starting goaltender at 3300 minutes, would face 12 more shots than Rinne but face 63 more high-danger shots throughout the course of the year. Pekka’s save percentage against high-danger shots last year was just .783; 28 points below the league average of .811. Is it plausible to say that if he faced 63 more high-danger shots, that Rinne would have surrendered 13 more goals? If a win equals about six goals; are the Preds about four points worse in the standings with Rinne in net than with a league average goaltender?
Well, it’s a bit more complicated than that. Using some fantastic visuals by Ian Fleming, we can break down Rinne’s performance over the last three seasons into even greater detail. Below is Pekka Rinne compared to the average goaltender making $6+ million per year. The Preds are on the hook for two more years of $7M Rinne before his contract expires. The chart shows Rinne below the league average of goaltenders in his tax bracket in every metric except for low-danger save percentage, showing him especially vulnerable to high-danger shots against. His backups represented by the orange dots have been markedly worse. This is why the emergence of Juuse Saros is key for Nashville.
Using the same SAVE chart from above created by more dedicated goalie gurus Ian Fleming and Nick Mercandante, there are two metrics that don’t shine too brightly on Rinne. The first is an adjGSAA/60. Yeah it’s an abomination of a name and they know it too. What that mess stands for is “adjusted goals saved above average per 60”, or if we rate each shot on its own merits, how much better or worse is the goalie we are talking about compared to league average? SAVE shows Rinne to be -0.16 below league average. According to this metric Nashville surrenders about one extra goal per 20 periods of Pekka Rinne than they would compared to the NHL average.
The other number is “Above Average Appearance Percentage”, or the total amount of starts where a goalies GSAA is above 0. Rinne checks in here at 48%
This is where some of the goaltending metrics can be a bit contradictory. If we use Rob Vollman’s Quality Start concept developed a few years ago and plot every goaltender in the NHL over the last four years with 40+ starts Rinne fares decently well in pure quality starts. He’s a bit better than league average in the same neighborhood as current NHLers Cam Talbot, Roberto Luongo and Robin Lehner.
On the other hand the other concerning aspect of Rinne’s body of work is his penchant for turning in what’s been dubbed a “really bad start.” He’s sharing the same neighborhood here with unheralded goalies such as Cam Ward, Jonathan Bernier and Mike Smith with an RBS just under 16%.
Lets Get Back to Rebounds
Rinne’s heat map is one you’d want to see if you were a goalie. The Predators with Rinne allow far less shots on the doorstep and in the slot than the NHL average. Do we attribute that to the defense or to Rinne himself?
Rinne is considered among the league’s best in rebound control due to his superb glove hand. Does his trapper reduce the amount of second chance shots he faces? The key question is, does his rebound acumen make him look worse against high-danger chances because he’s seeing less rebounds that are easier to save, and more tips or royal-road shots that are comparatively harder to save? Chris Boyle pointed out nearly four years ago that Royal Road shots and deflections are the most difficult shots for a goalie to stop. If we really want to get into shot types and goalie analytics Double Blue is doing work here, but that kind of data is proprietary.
Hockey Viz shows us that without Rinne in net there are far more shots against on the doorstep, especially on the stick side; but unless someone wants to manually track rebounds or perhaps expected goals emerges a bit more, we are left with those questions to ask.
Last Year Was Better
Rinne had a dismal 2015-2016 season with a save percentage of just .908. His last few years have shown us a bit of a roller coaster ride. His GAA fell from 2.48 to 2.42. Not a huge jump but the other numbers tell us more. His GSAA went from -12.51 to 8.05. His SAVE chart below is compared to Vezina winner Sergei Bobrovsky. The positives here are above average results in low and medium danger shots, and above average results in quality appearances. In 56% of his starts, his GA was lower than xGA. Contrary to those positives he’s still below league average in high-danger chances and just below the league average in xGSAA/60 at -0.09.
So what happened between the 2015 season and the 2016 season? Was his performance two years ago just an aberration? Was it simply goaltender variance from year to year? Was Rinne dinged up? Is P.K. Subban that much better than Shea Weber, or was it the emergence of the Nashville defense as perhaps the leagues best?
The Effects of Aging
Rinne turns 35 in November, pretty much uncharted territory for goalies. Only Roberto Luongo, Ryan Miller and Craig Andersen even sniffed 40 starts in a 35+ aged season last year. We will get a trio of additions this year though. Henik Lundqvist and Mike Smith will celebrate their 35th birthdays sometime during the season.
Goaltender Aging Curves
The two more recent goalie aging curves are this one by @Garik16
and this one by @Fooled_By_Grit
If you are the reading type, you can dig deeper here, here, here, and here. With either method we can expect a change for the negative for Rinne entering his age 35 year of either -0.003 or -0.004. All other things remaining constant, Rinne’s save percentage this coming season should be .914 or .915 based purely on aging.
Eric Tulsky looked at survivorship bias as well: perhaps even the three or four point decline is underestimating the effect because many goalies with starting gigs in a 35+ season have been world class or are Hall of Fame worthy.
Adjusted Save Percentage
Another trend of goaltender analytics has been to evaluate a goaltender’s 5 on 5 save percentage, since 4 on 5 save percentage is highly volatile from year to year, and some teams are much more prone to taking penalties than others (Jets, Winnipeg). The league average here is .923. The trend for Rinne has been slightly downward but not in a linear fashion. Nothing in hockey is linear.
Take Care of What We Love
Whatever happened to Rinne the last third of the season last year? It’s the only season he’s had since 2011-2012 where his save percentage increased down the stretch. Maybe the playoff chase reinvigorated him.
The picture here is obvious. Even before his hip issues in 2013 he already showed signs of decline in overall performance as his total games crept into the high 50s each year. That trend has continued until the run he had last spring.
Thankfully, and perhaps for the first time in years, the Preds have had a reliable backup in Juuse Saros. In 21 starts last season, the younger Finn posted a 10-8-3 record with a .923 save percentage and a 2.35 GAA. His SAVE profile is eerily similar to Rinne’s with a slight nod in xGSAA/60.
Coach Laviolette should pace Rinne at about 50 starts. Tab Saros for 30 or so, which will not only ensure the transition between the two when Saros ultimately takes over the crease, but it will keep the then 35 year old Rinne fresh come playoff time. It’s clear how much Nashville means to Rinne. Keep him ready for the long Cup run. Saros is one of the top goalie prospects in the league. He can be trusted against any opponent on any night. He won’t need to be sheltered.
What Does 2017-2018 Have in Store?
Nashville needs to get off to a good start. In pretty much every metric there is, Nashville didn’t really get going until around game 18 last year. Nashville returned home from St. Louis on November 19th with only 17 points in 17 games. They played at a 97 point pace the rest of the way and saw their goal and possession metrics turn positive, where they remained the rest of the season.
On the injury front Ryan Ellis will be out until at least January. Nick Bonino is still recovering from a leg injury and his status for the season opener is in doubt, leaving the team with a hole in their top four and a huge hole down the middle of their forward lineup.
The Central Division is perhaps the toughest in hockey, with every team except Colorado expecting to be in the mix for a playoff spot. The margin for error is likely to be razor thin, but as we witnessed last spring the key is to just get in. Toss in the proverbial Stanley Cup hangover and now the start of the season looks more important than ever.
Looking ahead to this season it’s plausible to see another Cup run out of this year, but hockey can be a fickle game. A realistic expectation for Rinne is about league average goaltending, which for a 35 year old is pretty damn good. Limit Rinne’s games to maximize his results, and let’s get one more Cup run out of him!