After the Predators lost to the Blackhawks on Saturday night by a score of 3-5, there were a number of folks questioning the coaching decision to start Marek Mazanec in place of Pekka Rinne. After all, Maz gave up three goals on the first five shots he faced while a $7 million goaltender watched from the bench.

Let’s go ahead and get this out of the way: starting Maz on Saturday was 100% the correct decision.

There are two main reasons for this, both of which deserve equal merit.

Starting Goalies on Zero Days Rest is a Terrible Idea

It doesn’t matter that Rinne hadn’t played a game since September 18th, a game where he gave up four goals to Team North America in the World Cup of Hockey. All the data suggests that starting goalies on zero days rest (aka, starting them on the second game of a back-to-back after they also played the first game) leads to a significant loss of production and effectiveness. That link there takes you to a 2013 analysis by Kurt R over at Broad Street Hockey, where he found the following pattern:

Your average goaltender sees a 21 point drop in production when starting a game on zero days rest. That’s an incredible difference. If an average goaltender consistently put up a .892 save percentage in the NHL, he would not be an average goaltender in the NHL. He would most likely be in another profession. Or named Olaf Kolzig.

But what about Pekka Rinne? How has he done in back-to-backs? Maybe he’s immune to Zero Rest Disease!

No, he isn’t. He is slightly better than your average goaltender but he still sees a significant drop in production.

Date Opponent Location Result Saves Shots Save % 12/29/08 Colorado Away L, 1-5 16 21 0.762 3/19/09 San Jose Away L, 2-3 (SO) 36 38 0.947 3/29/09 Detroit Away W, 4-3 33 36 0.917 04/10/09 Minnesota Away L, 4-8 29 35 0.829 10/15/09 Chicago Home L, 1-3 27 30 0.900 10/29/09 Chicago Home W, 2-0 22 22 1.000 03/12/10 Anaheim Away W, 1-0 31 31 1.000 03/21/10 St. Louis Away W, 3-2 23 25 0.920 11/27/10 New York R Home L, 1-2 (SO) 23 24 0.958 12/01/10 Columbus Away W, 4-3 28 31 0.903 01/24/11 Calgary Away L, 1-3 24 27 0.889 02/27/11 Columbus Home W, 3-2 25 27 0.926 04/09/11 St. Louis Away L, 0-2 23 25 0.920 10/08/11 St. Louis Away W, 4-2 31 33 0.939 11/23/11 Minnesota Away L, 2-3 27 30 0.900 12/23/11 Dallas Away L, 3-6 4 7 0.571 01/24/12 Chicago Away W, 3-1 24 25 0.960 03/25/12 Chicago Away W, 6-1 24 25 0.960 03/31/12 Chicago Home L, 4-5 32 37 0.865 02/19/13 Detroit Home W, 4-3 26 29 0.897 02/23/13 Detroit Away L, 0-4 23 27 0.852 03/09/13 Minnesota Home L, 2-1 (SO) 28 29 0.966 03/15/13 Calgary Away L, 3-6 0 2 0.000 04/02/13 Colorado Home W, 3-1 25 26 0.962 04/07/13 Chicago Away L, 3-5 35 39 0.897 04/15/13 Vancouver Home L, 2-5 19 24 0.792 10/04/13 Colorado Away L, 1-3 33 35 0.943 03/15/14 St. Louis Home L, 1-4 22 26 0.846 12/30/14 St. Louis Home W, 3-2 26 28 0.929 03/15/15 Anaheim Away L, 2-4 24 28 0.857 11/21/15 Minnesota Away L, 0-4 23 27 0.852 03/29/16 Dallas Away L, 2-5 20 23 0.870 32 starts on zero days rest 12-17-3 786 872 0.901 436 career starts 239-136-53 11378 12403 0.917

On average, Rinne sees about a 16 point drop in production when starting games on zero days rest. Better than the average drop in production that Kurt found, but still significantly diminished. It should also be noted that a lot of his more successful games on zero days rest were about 5-6 years ago. His recent numbers are much worse.

Backups Deserve Starts. "Life After Pekka" is Unavoidable.

Carter Hutton jokes aside, the Predators have to be able to develop more than one goalie at a time. Currently, the Preds have two solid understudies in net. One of those, Juuse Saros, still needs time in Milwaukee. But Marek Mazenec is 25 years old and at this point only has 28 NHL starts. It’s impossible to even know Maz’s caliber as a goalie because he has started so few meaningful games.

Pekka Rinne’s contract runs through the 2018-19 season. While I would love to see him play well over the next three years, it’s pretty insane to think he can produce his usual career numbers as a 33-35 year old goalie in the NHL. But even if he does, there has to be a plan in place for the future. Whether the successor of Rinne is Mazanec or Saros or a player to be named later, there has to be a reasonable path to success in the NHL. A reasonable path does not mean starting a "rookie" goalie for 60-70 starts after not having more than a handful of starts in a previous season.

The league is changing with regards to goalies. There are only a few teams with the "workhorse" goalie mindset these days: the Capitals with Braden Holtby, the Kings with Jonathan Quick, and the Canadiens with Carey Price come to mind. Other teams are finding ways to have multiple goalies that can start and play well. Just last year, several teams found success with this model. The Blues with Brian Elliott and Jake Allen. The Islanders with Jaroslav Halak and Thomas Greiss. The Ducks with Frederik Andersen and John Gibson. It looks like the Lightning will use more of Andre Vasilevskiy along with Ben Bishop.

Starting Mazanec on Saturday set an important precedent for this 2016-17 Predators team. If the trend continues, and if the coaching staff commits to not starting Rinne for 60+ games, the Predators will be able to successfully mask the one glaring weakness on their team.