Offensive players generally will be used in more offensive situations even in 5v5 while defensive players, especially those paired with another defensive player, are sometimes almost reserved for the defensive zone minutes. This stat is heavily slanted towards those who don’t see the defensive zone.
Miller plays with Fox, Pettersson plays with Karlsson, and Walker plays with Gostisbehere, according to daily faceoff.
Yes, players used largely in pure defensive roles or against tough competition will be at a raw disadvantage by these metrics (there are better ones out there that try to adjust for usage, QoC, and QoT though). I know this and already acknowledged it.
Again though, as I said, there are guys who play tough minutes that are on the positive side of the ledger. K'Andre Miller plays the tough competition with Fox. Gavrikov plays with Anderson and they are the team's shutdown pair.
Good defensive players, even given their deployment, can still rate highly by these metrics. Last season, McDonagh, Alex Vlasic, Gudas, Nick Seeler were all near the top of the league by relative xG. They play the defensive minutes for their teams.
Nothing wrong with rating them low, but we’re missing the other corners of the graph — defensive players who play really well, and offensive defensemen who are not producing.
Basically, god help a low-offense shutdown guy who ends up on a bad team or just in front of a bad goalie. He’ll be rated miles worse than a third pairing offensive specialist who isn’t producing but is on a good enough team that his GF/GA breaks even.
Again, defensive defenseman can outperform their usage - that is what defines an actually good defensive defenseman. If you're a defensive defenseman that's just getting shelled, you're not really doing your job. Ideally your designated shutdown guys can at least break even in tough usage, which basically subsidizes the rest of your team to get softer minutes. If they can't accomplish this, they're not really doing much for you.
I've named several players that
do accomplish this.
You wanted the opposite side of the ledger? Last season, Tyson Barrie, Drysdale, and Calen Addison were some of the worst defensemen in the league by relative xG. They are guys that get soft, offensive deployment. Usage isn't going to completely obscure whether a guy is good or not.