How Unusual Was Frederik Andersen’s Cold Streak?

The Toronto Maple Leafs made a big bet on Frederik Andersen this summer when they acquired him for Jonathan Bernier and two high draft picks, then proceeded to sign Andersen to a long-term contract extension.  When the new starter struggled to start the season, fans and media alike were concerned about what was going on with the Leafs’ starting goalie.  The situation culminated in a tense exchange between a reporter and Mike Babcock earlier this week:

Babcock said it was only five games and urged caution, but there remained a sense of concern among fans. This was the second straight year in which the Leafs’ starting goalie had a very rough stretch of games near the beginning of the season, as Jonathan Bernier went through something of a collapse in November of 2015-16.  At the time I argued that Bernier was likely just going through a rough stretch and would likely see a return to form before long.  That turned out to be true, as Bernier played right around his career average once the Leafs called him back up to the NHL following a brief stint with the Toronto Marlies.

It would seem like Babcock is correct to say that we shouldn’t worry too much about five games of bad goaltending.  In the two games since then, Andersen’s SV% is .935, so his numbers are already starting to rebound.

I wondered if Andersen had ever gone through a stretch of five games as bad as the five he had to start this season, and if so, how common that kind of performance is.  Should we be concerned that Andersen’s hit a new low, or is this just the kind of thing that goalies go through from time-to-time.

To find out the answer to that question, I’ve put together a chart of a rolling 5-game SV% since Andersen first entered the NHL in 2013-14 (for perspective, his career average was .918 heading into this season):

You can see that Andersen’s current patch is one of the worst of his career, but it’s not unprecedented.  He had similar stretches of five games below .900 around game 75 in his career, as well as one around game 100.  And while his recent numbers have been rough, they aren’t the worst he’s ever done, as he’s hit lower lows twice before, roughly 1/3 and 2/3 of the way through his career.  It’s also worth noting that the current string of low totals stretches back into the end of the previous season, so it’s not as though his numbers immediately plummeted upon joining the Leafs.

In fact, of the 127 different five-game samples looked at here, Andersen’s rolling SV% was below .900 in 34 of them.  That’s 27% of his career.  It’s unfortunate that he struggled through his first few games in a new uniform, but this is just the sort of thing that happens to NHL goalies.  SV% is a very volatile statistic, and sometimes it’ll look bad for a while.

To put this in some perspective, here’s the list of Andersen’s worst five-game SV% along with the season in which they took place:

It’s true that some of the worst stretches of Andersen’s career have come this season, but it’s also true that they’re far from unprecedented.  In fact, half of the worst five-game samples in Andersen’s career happened last season, primarily during the downturn around game 100 of his career.  But it’s worth noting that Andersen also had one of the best periods of his career immediately prior to that downswing, as well as an even better stretch directly afterward.

This highlights something interesting about the chart above: a very small number of the five-game samples are all that close to Andersen’s career SV%.  It spikes up above and swoops down below, but it’s very uneven, and rarely does it actually sit near the overall average.  You can sort of see where the long-term trend hangs out, but the individual samples are mostly pretty far apart from it.  Goalie performance swings so wildly over small spans of time that we need to be cautious not to read too deeply into a bad patch or a hot streak.  These things tend to even out over time, but for SV% that time can be pretty long.

So fans should try not to worry too much about the fact that Andersen had a few bad games at the start of this season.  It’s the kind of thing all goalies go through on occasion.  Andersen’s gone through similar patterns before, but he’s always bounced back in the past, and there’s no reason to believe it’ll be any different this time.