Barry Trotz shook up his defensive pairings a few weeks ago and in doing so he reunited John Carlson and Karl Alzner as the Caps shutdown defensive pair. Carlson and Alzner have skated just over 3,000 minutes together in their career, but only 212 of those minutes have been during the Trotz regime.
But 128 of those 212 minutes have come since the recent reunion. The pair has been Trotz’s first choice to shutdown the top offensive players on the Caps’ opponent any given night. Unfortunately for the Caps, the reunion isn’t going very well. The Caps are getting outplayed when they’re on the ice. This pairing either needs to be broken up or have the difficulty of their assignments reduced.
Five different pairings have played 100-plus minutes of 5-on-5 hockey for the Caps so far this season. Here’s how each of them have done in terms of shot attempt percentage (In case anyone is curious, we use shot attempts because it’s the best predictor of a team’s future performance in terms of goals for and goals against).
| Pairing | Shot Attempt % (relative SA%) |
|---|---|
| Orpik and Schmidt | 59.0 (+6.5) |
| Niskanen and Orlov | 58.1 (+5.0) |
| Orlov and Carlson | 54.2 (+0.6) |
| Niskanen and Alzner | 52.9 (-1.8) |
| Alzner and Carlson | 46.9 (-8.4) |
As you can see, the Alzner/Calrson pairing is significantly worse than any other pairing the Caps have used this season. The difference between the Caps second worst puck possession pairing (Niskanen/Alzner) and Carlzner, a gap of 6 percentage points, can be the difference between a solid Cup contender and a team that’s going to pick in the lottery.
Think about that. With any defensive pairing other than Carlzner on the ice, the Caps possession suggests they are a legit threat to win the Cup. But, when Carlzner hops over the boards, not only does the team’s play take a nosedive, it drops all the way towards the bottom of the league.
But we can add more context to the shot attempts. Here’s how all of the pairing do in terms of scoring chances. The number is the percentage of the overall scoring chances that are for the Caps when each duo is on the ice.
| Pairing | Scoring Chance % (relative SC%) |
|---|---|
| Orpik and Schmidt | 60.3 (+12.4) |
| Orlov and Carlson | 52.2 (+4.3) |
| Alzner and Carlson | 48.3 (+0.2) |
| Niskanen and Orlov | 44.3 (-3.6) |
| Niskanen and Alzner | 40.8 (-10.5) |
The story here isn’t as dark. Alzner and Carlson do okay as a duo in terms of scoring chances. Two things to note here is that scoring chances are a much smaller sample than shot attempts, so the numbers are less stable, and what scoring chances mean for a team’s future performance is much less clear than what shot attempts mean.
Last, we can look at expected goals. Expected goals are, in a way, a combination of shot attempt and scoring chance numbers to tell us how well a team or player should be performing in terms of goals scored. This can be handy because goals can be so fluky in small samples. An expected goals for percentage (xGF%) can tell us how well a team or player should be performing, attempting to drown out the noise that fluke goals and bounces can cause in small samples.
| Pairing | Expected goals for % (relative xGF%) |
|---|---|
| Orpik and Schmidt | 59.9 (+10.9) |
| Orlov and Carlson | 49.8 (-0.6) |
| Niskanen and Alzner | 49.6 (+0.7) |
| Alzner and Carlson | 49.2 (-1.5) |
| Niskanen and Orlov | 48.3(-1.5) |
Here we see the Alzner/Carlson duo again below 50 percent, but not performing nearly as poorly as they have in shot attempts. Due to the overwhelming evidence against this pairing in shot attempts, anything less than a solid rebuttal from other numbers make the shot attempt percentage impossible to ignore.
A discussion of these defensive pairings wouldn’t be complete without talking about the assignments they are given by the coaching staff. Before diving too far into that, we should consider that there’s evidence to suggest that zone starts and quality of competition have very little impact on puck possession numbers over the course of a season.
And, if we are providing the context of quality of competition, we also need to consider quality of teammate. Because Alzner and Carlson are often pitted against top forwards, they also have the luxury of often skating with the Caps best forwards. This hasn’t helped. Of their 112 minutes together, Carlzner has skated 49 of them with Nicklas Backstrom and the team has seen just 46 percent of the shot attempt during this time. Turning Backstrom into a 46-percent possession player is another sign this duo isn’t working.
But, it’d be foolish to think usage isn’t influencing the numbers here a bit. After all, no one really thinks that an Orpik/Schmidt pairing is actually ~14 percentage points better than a Carlson/Alzner pairing if all things were equal. But, on the flip side, no one should really believe that zone starts and quality of competition are the only reason an Orpik/Schmidt pairing is actually ~14 percentage points better than a Carlson/Alzner pairing. After all, Niskanen and Alzner were the team’s shutdown pair for the early part of the season, and they performed much, much better than Carlzner in that role.
And that’s an important thing to consider. The Caps were performing worse with Niskanen and Alzner on the ice than when they are off (1.8 percentage points less of the overall shot attempts), but the team was still getting over 52 percent of the overall shot attempts. That’s not bad. Further, a drop of 1.8 percentage points is fairly small when considering this is the duo handling the toughest assignments.
But when Carlzner is on the ice, not only are the Caps well below the 50-percent possession mark, but their overall puck possession drops by over 8 percentage points. If a pairing turns a top possession team into one of the worst in the league, any context of how this pair is used isn’t enough to override the downright terrible performance. If a kid brought home all Ds in honor classes, would we excuse the performance because the kid was taking tough classes, or would we look to move the kid into classes where he or she could be more successful? The latter seems the obvious choice.
Carlzner has been deployed as the Caps top defensive pairing. They face the toughest opponents and start more shifts in the defensive zone than any other pairing. However, their performance has been so poor that it’s clear they can’t handle this role. The duo either needs to be broken up or have the difficulty of their assignments reduced significantly.
All stats from Corsica
Headline image: Rob Carr
