Claude Julien became the first coaching casualty of the 2020-2021 season earlier this week as the Montreal Canadiens have struggled over the last couple of weeks and team looks for a spark. Mid-season coaching changes have become commonplace in today’s NHL as teams look to change their fortunes during the campaign. Let’s look at the impact a coach can have in the NHL.
Coaches are responsible for defining and implementing systems, deploying players to create favorable matchups and providing leadership and motivation. Overall team metrics should give us the best insight into the impact a coach is having on a team, although it’s difficult to extract since player performance affects these metrics as well. We need to look to previous coaching changes to see the potential impact.
2018-2019 St Louis Blues
Looking back to the 2018-2019 season, the St Louis Blues made one of the seven mid-season coaching changes that year. They provide an excellent example to study the positive impact a coaching change can have on a team. The Blues were expected to be a strong team going into the season yet sat in last place in their division and 30th in the league when Craig Berube took over the head coaching duties in mid-November. The coaching change resulted in a remarkable turnaround that not only saw the Blues make the playoffs, but they also went on to win the Stanley Cup that season.
In a previous series of posts, I examined the high level team statistics that successful teams have in common and we can use the same stats to see the impact of the coaching change on the Blues. We’ll look at goals for an against, as well as scoring opportunities for and against. In the plots below, we can see the metrics for the Blues under Mike Yeo for the first 19 games, under Craig Berube for the remainder of the regular season, and for the complete regular season. The rest of the teams are plotted showing the full season statistics for reference.
We see the dramatic change that the Blues undertook on these plots. The most striking change is their improved defense. They transformed from one of the worst defensive teams in the league under Mike Yeo, allowing high rates of scoring chances and goals against, to the best defensive team in the league under Craig Berube. The Blues’ offense also improved significantly in the number of scoring chances they generated, possibly due to their improved defense. Although they didn’t convert their chances at as high a rate as early in the season, they were still effective enough to greatly improve their overall goal differential. We can see the Blues clearly changed their approach to a more effective defensive system when they made their coaching change and it brought the team to a completely different level.
2020-2021 Montreal Canadiens
Now let’s jump back to this year’s version of the Montreal Canadiens. Claude Julien was fired after 18 games this season, which is a very similar sample size to the Blues in their cup winning season where Mike Yeo was fired 19 games in. In a typical season, it generally takes about 20 games for the standings to settle out so this is probably a large enough sample size to give us a reasonable prediction of long term performance. Let’s take a look at how the Canadiens compare to the rest of the league on the same offensive and defensive metrics to see if they are poised for a turnaround under a new coach.
Looking at these metrics, it’s hard to see how the Canadiens could benefit from a coaching change like the Blues did two year ago. They are already the best defensive team in the league and one of the best offensively. So why did the Canadiens feel like a coaching change was necessary?
As I noted off the top, the Canadiens started off the season 7-2-1 which may have set some unfortunately high expectations. Following the hot start, they fell to 2-4-2 prior to the coaching change. Let’s look at the metrics for these two segments of their season.
| GF | xGF | GA | xGA | |
| Games 1-10 | 3.64 | 2.41 | 1.75 | 1.82 |
| Games 11-18 | 2.28 | 2.31 | 1.82 | 1.79 |
| Season Total | 3.00 | 2.36 | 1.79 | 1.81 |
The metrics are very similar to the two segments of the season, except for the actual goals for. Let’s add these to the offense plot.
It doesn’t look like the Canadiens’ overall execution of their systems has changed through their recent struggles and they still have strong underlying numbers which suggest their recent struggle may be more of a bump in the road than a systemic problem. The big difference we see is their offensive conversion rate. Montreal started the season with an incredibly high goals to expected goals ratio and looks like it is regressing toward a more sustainable rate.
Time will tell us whether this coaching change works out for the Canadiens but it doesn’t look like they are primed for a big improvement to their systems like the 2018-2019 St Louis Blues.
What do you think? Was Montreal’s coaching change needed? Will it bring the team to another level?
