Sanheim has been our No. 1 defenseman this season even if he hasn't been used like one. That alone -- being the best defenseman on your team -- is a reasonable standard to call someone "one of the best defensemen in the league."
His metrics are off-the-charts fantastic. As JoJo mentioned, they have been from the start of his career. How good are they? He's the only person in the history of hockey who has been able to carry Andrew MacDonald to genuinely positive possession numbers. .
I'm not the biggest slave to metrics. When the guys at BSH said that Matt Carle was just like Ryan Suter, I just laughed. Because f*** Matt Carle. But Sanheim has always passed the eye test to me. He looks ridiculously calm and poised and just makes quietly effective plays in the defensive zone. Does he make mistakes? Sure. He was late in covering his man on one of the BJs' goals yesterday, but that was after he made a tremendous play while pressured by two forwards to get the puck out of danger and over to Provorov, who fumbled it back.
Anyway, Mark Howe was one of my favorite players too. He was 77 times the player Paul Coffey was, who stole two Norris Trophies from him. Sanheim reminds me a lot of Howe, and probably more than any other player I've seen since then. As great as Howe was, his name isn't sacred. If people can compare Rasmus Dahlin to Lidstrom you don't have to get your panties in a bunch if I bring up Howe's name.