There has been some talk out there about Jacob Trouba not developing as one would hope, or that he has failed to live up to his rookie season hype. This could not be further from the truth.
Some of this has been driven by a Trouba’s point totals falling or him playing a less visually-noticeable dynamic game, while another part may come from his permanent role in Mark Stuart babysitting hurting him.
Let’s take a look into how Jacob Trouba has slowly grown into one of the more effective two-way defenders in the NHL.
Why Trouba’s Scoring Dropped
People were pretty excited for the young defender hailing from Rochester Michigan after putting up 29 points in a 65 game, injury-shortened, season. The next year Trouba only put up 22 points in the same number of games, and then only scored 21 over a nearly full 81 game season for 2015-2016.
The perception of success and development issues likely began with unreasonable expectations being set from the start with inflated on-ice and personal shooting percentages.
The Jets scored on a likely unsustainable 10 percent of shots on goal with Trouba on the ice for his rookie season, which dropped to a more sustainable 8.5 percent the following two seasons. This has caused a fall in goals scored while Trouba is on the ice that he can pick up assists from, despite the Jets actually generating more scoring chances per minute than they did prior with Trouba on the ice.
In addition, Trouba assisted on 30 percent of the goals the Jets scored while he was on the ice for 5v5 minutes. This number dropped to 24 percent the next season, and then 15 percent this past year. It’s likely that Trouba will bounce back here, although one should not expect much more than mid-twenties for sustainable results.
The excitable rookie defender was often caught up with offensive rushes, finding himself a few meters from the net, picking up a few goals, and putting up a fairly high personal shooting percentage of 8.3 for all minutes. He’s since cleaned up his risk game, and while the overall impact has been positive from this change, his career shooting percentage has dropped to 6.4 percent, after a 4.5 and 5.0 shooting percentage seasons.
One of the other primary factors has been a drop in power play usage. In his rookie season, Trouba averaged about 2.0 minutes of power play ice time per 60 minutes of team play. This dropped each successive year with the acquisition of Tyler Myers (despite Myers being a very poor power play defender option) with Trouba averaging about 1.2 minutes of power play ice time per 60 minutes of team play.
Over the past two seasons, Myers and Trouba have scored an identical 9 points on the power play, despite Myers receiving nearly an extra 60 percent share of power play ice time.
Two-Way Game Improvement
As mentioned earlier, the change in Trouba’s play has been for the better for the Jets, despite it hurting his personal scoring numbers.
The graph above shows the Jets expected share of 5v5 goals over a 25 game rolling average when Trouba is on the ice versus when he’s on the bench. In other words, this shows how often the Jets have done better with Trouba on the ice than the average alternative. The right-shot defender each season has spent less and less time below zero, and has been better each season on average than the last.
First four columns are score, venue, and zone adjusted courtesy of Corsica, while the final two are simply 5v5 courtesy of Hockey Analysis.
At a surface level, it almost looks as though Trouba actually peaked last season in the two-way numbers. This is the season where Trouba had his best shot differential (Corsi), expected goal differential (xGoals), and unblocked shot differential (Fenwick).
These numbers do not take into account team quality effects though, and when we look at the relative numbers the story changes slightly. In relative Corsi (Jets share of all shots with Trouba on ice versus on bench) we see that the Jets do moderately better with Trouba on the ice. This progression though does not account for blocked shots, which is a larger part of a defender’s performance than it is for a forward.
Expected Goals and Fenwick do account for blocked shots, and we see a more positive and consistent growth curve there. The relative Fenwick model above is slightly different than the relative Corsi or xGoals model.
The relative Fenwick model is relative to teammates, which instead of Jets with Trouba on the ice versus on the bench, looks at the weighted average of Trouba’s linemates with him versus without him. In many ways, this model is a check to see of Trouba’s positive relative numbers from the other models are due to Trouba’s performance or his linemates pulling him up.
In short, Trouba’s progression seems to be a fairly consistent and positive one in the two-way numbers when you account for team performance and quality of linemates.
The Mark Stuart Effect
Speaking of linemates, we cannot talk about Jacob Trouba without looking at the impact of linemates on the eyetest, results, and opportunity.
First off, I want to mention that the eyetest is in-fact impacted by usage just like the numbers are. The weaker your team and linemates are, the tougher your usage is, and the more time you spend in the defensive zone, the more opportunities you have to make errors in the defensive zone.
Due to heuristics, the human mind tends to remember the big, flashy events more often than the small common pieces that adds up to significant impact. A mistake in a defensive zone is more likely to end up a goal against than one in the offensive zone. A good play in the offensive zone is more likely to end up a goal for than one in the defensive zone. A mistake is still a mistake, and a good play is still a good play, but not all will be remembered equally.
For the most part, Trouba has played in one of two different situations: with good players while on his offhand side or on his natural side with Mark Stuart.
We know for a fact that being on ones offhanded side has a quantifiable negative impact on the results for a defender (see work by Matt Cane and Domenic Galamini). But, we also know full well that Mark Stuart has a severely negative impact on the results for any one he plays with.
So, when we look at how the the results split with and without Stuart for Jacob Trouba, we have to remember that Trouba is also playing away from Stuart in a non-optimal situation:
Trouba scoring increases by about 24 percent when away from Mark Stuart. If we extrapolate Trouba’s point pace without Stuart over his career minutes, his 5v5 point totals jump from 42 to 48, an increase of 14 percent. Give Trouba the extra power play icetime that was given to Myers, and Trouba gains an extra 9-10 points to his 72 point career totals.
This is not that surprising, as the Jets are generating about 7 percent more shot volume when Trouba is away from Stuart than when the two are together. Not only do the Jets improve in shot volume, but also suppression, as the Jets allow 5 percent fewer shots against per sixty minutes of play.
In the end, the Jets control a larger share of shots, while also controlling a larger share of goals. Not shown here is that the Jets expected share of goals (which adds shot quality to quantity component) suggests a similar gap with the duo being an xGoal% of 50.5 together, but Stuart and Trouba posting 48.0 and 53.0 when apart.
This improvement all happened despite Trouba playing on his offhanded side for most of that time.
The Jets outshot their opponents by 7.93 shots per sixty minutes with Trouba away from Stuart; however, we expect that result to be depreciated by two right-shot defenders playing together by about 2.05 shots per sixty minutes. This would mean Trouba’s “true talent” performance away from Stuart is likely closer to 54.3 percent Corsi rather than the 53.5 percent we observed.