It was only 2016-2017 when Vlasic’s possession stats started to drop off. Prior to that, they were consistently very strong.
However, there is some evidence that says that even when his numbers had dropped off, they were due to deployment and partners. If you look at something like Evolving Wild’s RAPM metric, which accounts for teammates, deployment, etc., Vlasic was still very good until 2018-2019.
2013-2014: +9.33 Corsi Impact/60
2014-2015: +2.52
2015-2016: +2.83
2016-2017: +1.52
2017-2018: +3.12
2018-2019: -2.43
His 2013-2014 season was truly phenomenal from a possession standpoint and he was never going to return to that. But every other season after that was still very good, and among defensemen with 1000 minutes, his per-minute impact ranked 67th or higher in every season. But now his possession numbers are terrible. And I can promise you once the numbers are released for this season, they will look horrible.
I think it’s time we start to consider that Dillon isn’t all that bad. This is the second year in a row he’s posted some pretty solid metrics. He hasn’t looked great at all times, but it’s not like anybody else on the defense has, and Dillon has posted some of the strongest results for two years running. He was horrible in the playoffs but maybe that was more of a blip on the radar.