clock menu more-arrow no yes mobile

Filed under:

Do midseason coaching changes actually help?

With Michel Therrien on the proverbial hot-seat, we must consider how successful previous mid-season coaching changes have been in the NHL.

Jean-Yves Ahern-USA TODAY Sports

The Montreal Canadiens are currently mired in one of the worst runs in franchise history. Naturally, that lack of success has led to a demand for change, whatever that change may be. For many, the shake-up the team needs begins and ends with the head coach. Never before has the heat been on Michel Therrien the way it is now.

It's difficult to argue with those who call for Therrien's departure. Since an incredible nine-game undefeated run to open the season, the Habs have been on a long fall down the standings. They currently sit on the outside of the playoff picture looking in, so the situation has become rather dire.

Back on December 3rd, the Canadiens faced the Washington Capitals on home ice. Their 3-2 loss to Alex Ovechkin and company was the first of a four-game losing streak, and the only real adversity the team had faced up to that point in the season.

Since then, the Canadiens record is a league worst 4-16-1, earning them just nine points over that 21 game span - a lowly 21.4% of the possible points available. The team's even strength goals-for to goals-against ratio has fallen from 1.44 to 0.63 since that date.

Shooting percentage and save percentage are down as well, to the point that the Habs sit at the bottom of the league with a 95.5 PDO, a measure of those two stats added together, the average being an even 100.

Despite all of this, Therrien's team continues to possess the puck the way analytics say should get them wins. Undoubtedly this is a confusing time for people who want to make the connection between Corsi and winning, as the Canadiens seem to be doing the opposite of what stats folks say they should be every year. There has been much discussion about why this may be the case, and while that is not the purpose of this article, there are many that deal with the reasons why it continues to be an issue.

At the end of the day, Marc Bergevin and his management staff need to make a decision about who the head coach of this team is going to be moving forward. Perhaps just as important a decision if the Habs choose to move past Therrien, is when to make the change.

More than a few fans have campaigned for that shoe to drop immediately. In reality, though, making a coaching change 47 games into the season brings with it some considerable challenges.

Does firing a coach mid-season work?

We need not look back very far to find cases of mid-season coach firings to base our analysis on. Two coaches have been let go in the NHL already this season - Todd Richards of the Columbus Blue Jackets, and Mike Johnston of the Pittsburgh Penguins, who were replaced by John Tortorella and Mike Sullivan respectively.

(All stats compiled from and

Richards' situation is a difficult one to draw many conclusions from. Lasting only seven games into the 2015-16 season, and winning none of them, the Blue Jackets former boss was not given much time to right the ship. His sample size is too small to look at meaningfully, though his possession metrics do appear to be better than Tortorella's. The latter, however, has clearly gotten more efficiency out of his players.

In Pittsburgh, however, the opposite may be true. Overall, the Penguins are playing a style of game in which they control the puck a lot more: their CF% has gone up from 48.3% to 54.6% since Sullivan's insertion. The results on the ice, however, have not followed.

This is an interesting case because Johnston left Pittsburgh with a winning 15-10-3 record, while Sullivan has gone just 6-7-4. The issue is clear, and it is identical to that of the Canadiens. The team may be generating enough shots to win hockey games, but they simply aren't converting; the issue that led to Johnston's firing remains after his departure, possibly a warning to heed when considering a premature change in Montreal.

Before this season, there are many more examples of  midseason coaching changes we can draw from. Three NHL head coaches were fired during the 2014-15 regular season, including the New Jersey Devils' Peter DeBoer, and Dallas Eakins of the Edmonton Oilers.

DeBoer was replaced by a number of coaches, including then-GM Lou Lamoriello, and the duo of Scott Stevens and Adam Oates. Meanwhile, in Edmonton, Oklahoma City Barons coach Todd Nelson took over when Eakins was relieved. Here, over a larger sample, we can see more harmonized trends with similar results in each case, although to different extents.

In both cases, the team's possession metrics suffered as a result of the change, while most other things seemed to improve. Possession seems to be a wildcard when it comes to coaching changes, as it depends heavily on the team and which coach is chosen as the replacement. For that reason it is difficult to say what overall effect a midseason change would have.

What we can see here is that these teams other numbers rose following the change. In New Jersey's case, an above-average PDO helped make up for faltering possession, bringing about a fairly large upswing in point percentage. Is this a trend that remains constant with other coaching changes, on other teams?

Paul MacLean was fired by the Ottawa Senators 27 games into the 2014-15 season. After Dave Cameron's promotion, the Senators and goaltender Andrew Hammond went on an improbable run to make the playoffs. Cameron brought with him a much more effective playing style for the Sens, which led to a favourable CF%, and an even higher PDO - which had already been a tick above average under MacLean. Unsurprisingly, this led to much better results.

A year earlier, the Winnipeg Jets parted ways with Claude Noel, who had been their coach since the NHL returned to the city in 2011. This firing is of particular interest to the Habs because of the timing - 47 games into the season, the point at which the Canadiens now stand. While Paul Maurice was unable to get the Jets into the playoffs, they certainly made a run, improving considerably in all areas.

Going back further, there is another significant coaching change that should probably be considered when looking at the situation Therrien currently finds himself in. John MacLean was fired from the New Jersey Devils in 2010, despite a score-adjusted CF% of 50.6 . This makes him the only fired coach included who shares one vital statistic with Therrien - that of favourable possession. Andrew Berkshire touched on this topic for SBN in 2014, and included a breakdown of MacLean's performance in New Jersey, as well as that of his successor Jacques Lemaire.

What this means

We can draw a number of things from this. The most notable is that similar trends that occur after nearly every replacement is hired. In six of seven examples, the team went on to an improved PDO, an improved GF:GA ratio, and an improved point percentage under their new coach. The outlier in each case is Pittsburgh, meaning either the move has just not had enough time to play out yet, or Sullivan is a bad replacement.

From this perspective, coaching changes seem to have great effect on a lot of teams, at least in terms of pure results if not in sustainability of play.

The thing to keep in mind here is that PDO has a fairly direct effect on the other two numbers rising. It stands to reason that rising shooting and save percentages would yield a rising goal differential - though not necessarily a positive goal differential. That would also lead to more points being earned throughout the season, as the team is competitive in more games.

The question is whether or not the coaching changes had much, if any, effect on the PDO rising. It should probably be expected that under normal circumstances, PDO would rise under a new coach's leadership. This is because low PDO often leads to slumps, which in turn lead to firings (though Paul MacLean was sacked with an average PDO, his team did not generate enough shots to succeed without overachieving). What we know about PDO, however, is that it eventually regresses back to the mean, so it's possible the new coaches are simply the benefactors of that occurrence.

Maybe the coaching changes were exactly what were called for. It is at least possible that seeing a coach fired and a new one put in place serves as a wake-up call, a much-needed spark

Meanwhile, only four coaches would improve on their predecessor's possession numbers. This facet is probably the least relevant currently - though not in the past, for Therrien - because it is heavily dependent on who the replacement is. It would actually be difficult for any replacement to match or improve on the possession numbers the Habs have already posted this year. Therrien's possession numbers are a topic more in line for a discussion on whether or not the Canadiens should even replace him in the first place, not when the change should happen if they do.

How it affects the Canadiens' decision

Therrien is a statistical anomaly as it currently stands. His team has been generating a massive amount of shots on goal, but has been executing woefully at both ends of the ice. There are a number of things this can be blamed on - questionable player usage and line deployment not the least of which - but the fact remains that he is on the hot-seat in a way that very few positive-possession coaches have been in recent years.

Therrien also stands out for just how bad a stretch this is. Of every fired coach named in this article, only Richards had a worse point percentage than does Therrien over the past 21 games. Only John MacLean in 2010 had a lower PDO. The vital question seems to be whether that can bounce back on it's own, or whether a new coach is needed to kickstart that process.

Of course, there are numerous factors which can't be measured that will come into play. One is whether or not the right replacement is available, or if the Habs feel more comfortable with an interim coach than they do with Therrien. The latter seems unlikely, given the struggles the assistants of this team have of their own.

If the replacement is someone readily available, such as Guy Boucher, perhaps this is a move that can be made. One must consider the other possibilities, though - many of whom are already behind NHL benches. The likes of Pascal Vincent, for example, may not be willing or able to even interview for such a move until the off-season.

The wisest plan of action, to the frustration of many, may be to give Therrien the rest of the season and see where that leaves us. After all, Carey Price is expected back soon; though that does little to solve the recurring issues that plague the Canadiens even through happier times.

In any event, this is obviously a trying time for the Canadiens and calls for some difficult decision making from the management. There are clear potential benefits, as well as major issues, that come with making a mid-season coaching change.

The decision to do so or not may hinge on which of those Marc Bergevin believes to outweigh the other.