In the second edition of theScore's Norris Trophy Power Rankings, three blue-liners under the age of 25 enter the fold. You can read October's rankings here.

ATOI = Average time on ice

SCF% = Percentage of scoring chances generated while player was on the ice at 5-on-5

HDCF% = Percentage of high-danger scoring chances generated while player was on the ice at 5-on-5

5. Kris Letang, Penguins

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GP G A P ATOI SCF% HDCF% 22 5 15 20 25:58 55.2 55.2

The Pittsburgh Penguins may be enduring a rough patch, but Letang is playing some of the best hockey of his career. He's the only player on this list with more takeaways (25) than giveaways (19) - an impressive feat considering how often he carries the puck.

4. Matt Dumba, Wild

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GP G A P ATOI SCF% HDCF% 24 10 8 18 24:00 56.2 56.4

The Minnesota Wild are often labeled as a good team that lacks a superstar talent, but that statement may need revising after Dumba's hot start. The 24-year-old leads all defensemen in goals, which is no fluke considering he ranks fourth among blue-liners in shots, and has a wicked slapper.

3. Morgan Rielly, Maple Leafs

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GP G A P ATOI SCF% HDCF% 25 9 18 27 22:04 50.5 51.0

Rielly enjoyed a breakout, 52-point season a year ago, but he's taken his game to another level through the first two months of the 2018-19 campaign. He's playing with confidence, jumping in on the rush with every appropriate opportunity he gets, and finishing his chances. He's also been strong defensively despite skating with Ron Hainsey, who's ill-suited for a top-pairing role at this point in his career.

2. Brent Burns, Sharks

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GP G A P ATOI SCF% HDCF% 25 3 22 25 23:48 55.6 54.9

Erik Karlsson is beginning to round into form after a slow start, but Burns has been the San Jose Sharks' best defenseman - and overall player - since the get-go this year. One of the biggest knocks on Burns' game was the amount of turnovers he committed, but he's averaging one less giveaway every two games than he did the past couple seasons.

1. Thomas Chabot, Senators

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GP G A P ATOI SCF% HDCF% 25 7 22 29 23:51 48.0 47.3

Erik who? Chabot's outstanding play has helped mend the broken hearts of Ottawa Senators fans still upset over the loss of a franchise icon. Twenty of Chabot's 29 points have come at 5-on-5, which is six more than the next defenseman. The 21-year-old's start is remarkable considering the lack of surrounding talent and experience.

Honorable mentions: Mark Giordano (Flames), John Carlson (Capitals)

(Advanced stats courtesy: Natural Stat Trick)