On Saturday night, the Leafs debuted a new set of defensive pairings, featuring Travis Dermott on the top pairing with newly-extended Morgan Rielly.
As a beneficiary of excellent play to start the season, Dermott seems to have earned this promotion, with his excellent play with Rasmus Sandin.
To honour that occasion, I thought it would be prudent to go over his career’s numbers thus far to get a sense of how good he could be in an expanded role, if it were to continue.
Dermott has played the majority of the last three years, half of the year before that, and the few games so far this year. So, we have about 4 season’s worth of data to work with. Let’s start with the overall picture, with all situations production and even-strength shot attempt stats, from Evolving Hockey:
|Player||Season||GP||TOI (all)||G||A1||A2||Points||TOI (EV)||GF%||SF%||FF%||CF%||xGF%|
It’s easy to see that he’s been a positive influence in goal-scoring (Goals For, GF%, a slightly better version of +/-), controlling the shot attempts (Corsi For, CF%), and even better when factoring in the location of those shots (Expected Goals For, xGF%).
But, obviously, we have to dig into that a little deeper. Here’s how those same stats look from season to season:
|Player||Season||GP||TOI (all)||G||A1||A2||Points||TOI (EV)||GF%||SF%||FF%||CF%||xGF%||PDO|
There are a few things I find interesting from this table:
- There was a significant drop in his CF% from 18-19 to 19-20, which he recovered from
- There was a significant drop in his GF% last year, corresponding with his worst PDO season
- He has been dominant this season so far in GF% and especially xGF%
The picture that this continues to paint is that Travis Dermott has been very good. He’s never dipped below 50% in either CF% or xGF%. Note: I consulted Natural Stat Trick and Money Puck for their Expected Goals models and they both have Dermott at 63% if you round to two digits (63.45% and 62.6%) However, we have to consider that the Leafs as a whole have not dipped below 50% in that time period either.
You could argue that Dermott has been helped by the fact that he plays with players that are good in these areas, who the Leafs generally try to keep in their roster. You could also argue that Dermott has played against strictly low competition and that he’s been helped by that.
Quality of Teammates, QoT, and Quality of Competition, QoC, are metrics that try to evaluate this context. They can both be important depending on the context. From this post by advanced stats gurus DTMAboutHeart and Ryan Stimson, for a defender, they are most influenced offensively by the defender they play with, and most influenced defensively by the forwards they play against, which seems abundantly obvious, but it’s good that it bears itself out in the numbers. That post measures quality in two ways, by average ice time and by Corsi, and found that the ice time measure was far more significant.
This player card, by JFresh Hockey, using a Wins Above Replacement (WAR) model by TopDownHockey, has both QoC and QoT, as measured using that WAR model.
We can see that, as expected, Dermott is very low in QoC, but also very low in QoT, meaning that he’s generally suffered from playing with poor defensive partners and forward lines. That’s also pretty much as expected, but it goes against our theory above that he’s being helped by playing on a Maple Leafs team full of good players.
This card also highlights that Dermott suffers a bit in offence, but is very strong in defence. That aligns with the analysis above on how QoT and QoC affect defenders.
Tonight, Dermott will be playing with significantly higher QoT, but also significantly higher QoC, so we can expect his statistical results to flip to being strong on offence and suffering a bit on defence.
Interestingly, overlaying some data visualizations from HockeyViz, including the Environment Distiller, we don’t see that to be the case in 2019-20 when he started to take on a 2nd pairing role as the season went on.
As expected, his defensive results on-ice were better in 2020 than in 2019, but contrary to expectation, his offensive abilities were also improved between these two seasons. There are a few possibilities for why that is, not limited to measurement error, but my hypothesis centers on the fact that he was playing a more offensive role in 2020 when paired with Zach Bogosian, versus in 2019 when he played a lot with the very-offensively-minded Tyson Barrie.
Next we will use HockeyViz’s Isolated Impact tool, which is best explained in its creator Micah Blake McCurdy’s own words:
The central task of player analysis is to separate out, as much as possible, the abilities of individual players from the effects of their teammates, their competition, and the choices of their coach. As much as possible, we want to know who is helping their team, and who is hurting it, and in what way.
We can see that, isolated from what effects that things outside of his control were having on him in either the 2019 or 2020 seasons, he generated basically exactly the same impact on his own. It will be tremendously interesting to see if he appears the same in this 2021-22 season; my expectation is that he will, certainly if he stays with this new top-pairing role. He’ll be playing even more time with the top line forwards, and with another very-offensively-minded defender in Morgan Rielly, so the Isolated Impact model will probably give the credit for offensive success to those players rather than to Dermott. This makes sense, since, other than his rookie season, he hasn’t shown to be a driver of offense.
Interestingly, Evolving Hockey’s Goals Above Replacement (GAR) model paints a different picture. We have not look at this model as of yet in this post, but I use it extensively as it is easy to use and seems to be very well fleshed out. Here’s how Dermott stacks up (use this Glossary if you’re unfamiliar with the acronyms in the table):
You can see that his even strength defense looks strong, as it did in McCurdy’s Isolated Impact model, but offensively, he had a great result in 2019-20 but a very bad one in 2020-21. This GAR model also attempts to contextualize things, so the effects of who Dermott played with are accounted for, but I would estimate that the strength of that accounting is much less than in the Isolated Impact model.
What to expect now?
We can be excited that Travis Dermott, the first pairing defender, has arrived; but the question to be answered is, will he stay? After one game, it would be frivolous to draw any conclusions. He and Rielly did not have the greatest game against the Red Wings on Saturday, as the pairing with the worst performance that night, relative to great showings from the other four defenders. But, they both were above 50% in shot attempts and expected goals, per Natural Stat Trick, at 5v5 and accounting for score and venue effects.
I don’t know that this grouping will last very long, as in the post game press conference, Keefe commented on how much he liked each of the defensive pairings, but added that:
In the third period, you need to be really connected, really focused, and really purposeful with how you play when we have leads, and I just thought we didn’t have enough of that.
And then later, when asked about how the Muzzin and Brodie pairing might fare in the long term:
We’ll see, because it’s not just that pairing, it’s: ‘how does it affect the other pairings?’ and who plays together, and all those types of things. Obviously as we look ahead into next week, we’ve got some very strong opponents, very deep forward groups coming in, and that presents some challenges that’s going to force us to look at it a little bit closer.
Now, it’s already been announced that the pairings will remain the same for the next game tonight against Vegas, but the comments above suggest to me that if the group continues to be unable to defend leads with dominance, or worse, isn’t defensively strong enough to take on the rough stretch of facing the Golden Knights, Lightning, and Bruins, we’ll probably see Justin Holl back in the lineup. I expect that will be the case for the Lightning game, and that it will not just effect the bottom pairing, but all three pairings, including this new Rielly-Dermott partnership. I can’t predict the future, but my instinct is telling me that even the uniquely youth-supportive Sheldon Keefe won’t suffer Holl’s healthy scratching for very long.
Altogether, Dermott is a good young defender, who excels at getting good defensive results, but has thus far struggled to drive much offense. Pairing him with Rielly, a veteran defender who has struggled to defend well, seems to be a well founded idea, so I hope that it continues. Here’s wishing him and the Maple Leafs all the best against Vegas tonight!