Evaluating the top 10 defensemen in ESPN's 2021 NHL position-by-position rankings is a study in competing philosophies on how to properly evaluate the position.

What metrics best define value for scoring defensemen or "defensive" defensemen? Do the elite have to do both well, or can one aspect compensate for the other?

I once asked Hockey Hall of Famer Nicklas Lidstrom how he evaluates other defensemen. He said the best of the best play instinctually, like he did. But there is one stat he scrutinizes: How much they play, and how good they are after playing a ton of minutes.

"That means you're playing all the power-play minutes but also have to have the ability to play against the opponents' top lines. You have to be able to defend," he told me. "I've seen players where their ice time goes up and their performance declines. They get fatigued. They make mistakes. If you're able to handle that ice time and still perform, or even get better as the game goes on, that's very important."

Lidstrom retired in 2012, so he wasn't a voter in our survey. We canvassed 10 active NHL players -- seven skaters, three goaltenders -- and 10 individuals in team hockey operations, from coaches to general managers to player personnel executives. The surveys were conducted over the past two months.

Respondents were asked to rank their top 10 players at center, winger, defenseman and goaltender, based on a predetermined list of the top 20 to 30 players at each position. Players who were ranked in the top 10 on each ballot were given a numerical score: No. 1 earned 10 points, No. 2 earned nine points and so on.

After ranking the wingers last week, here are the positional rankings for defensemen for the 2020-21 season, according to those in the NHL we surveyed. The blueliners who didn't make the cut are as noteworthy as those who did.

Stats are collected from sites such as Natural Stat Trick, Hockey Reference and Evolving Hockey.

1. Victor Hedman, Tampa Bay Lightning
182 points | Age: 30

I've made the case that the Lightning defenseman could be the best all-around hockey player in the world. Our survey respondents agreed that Hedman is, at the very least, the best defenseman in the world. He was ranked No. 1 on 14 of the 20 ballots. Two more had him second. Two more had him third.

"He's just a hell of a player," said one NHL coach.

Hedman, 30, has played every season with the Lightning since coming into the NHL as a 19-year-old in 2009-10. He is second to John Carlson of the Capitals in points-per-game average among defensemen since the 2017-18 season (0.83). His plus-98 places him firmly at No. 1 in that span, ahead of Zdeno Chara (+82).

Hedman won the Conn Smythe Trophy as playoff MVP last season, leading the Lightning to their Stanley Cup championship with 22 points in 25 games and 26 minutes, 28 seconds of average ice time. He's been a Norris Trophy finalist in four straight seasons, winning the award in 2017-18 for the first and only time.

He controls play in his own zone as a defensive stopper. He has been on the plus side of puck possession in eight straight seasons. While Hedman is no doubt the beneficiary of having an incredible assemblage of offensive talent around him, he's also an integral part of that offense with his puck-rushing and passing skills.

One of the aspects of his game that doesn't get enough attention: That the Lightning have been able to play him with anyone and still Hedman excels. He had four different primary defensive partners -- Jan Rutta, Dan Girardi, Jake Dotchin and Anton Stralman -- during his four straight Norris nominations.

"Hedman came in young. He had a longer runway than other young players," Lidstrom told me recently, "but boy, did he ever take off, in every aspect of his game."

Speaking of younger players...