It is the season of the rookie in the NHL, and not just because of high-scoring forwards like Toronto's Auston Matthews and Winnipeg's Patrik Laine, or Pittsburgh goalie Matt Murray. The biggest surprise of this season is how eight teams are using rookies on their top defensive pairing.
Looking back through recent history, it is unusual for there to be more than one or two particularly exceptional defensemen to play on the top pair in their rookie season. In 2015-16, for example, there were only occasional stretches of the season when rookies like Carolina's Jaccob Slavin, Edmonton's Darnell Nurse and Philadelphia's Shayne Gostisbehere were on the top tandem. Right now, there are eight rookies being employed on the main duo.
Not every team is using a rookie defenseman in the top two for the same reason. Some teams are blessed with one of those rare and particularly talented prospects, like Zach Werenski of the Columbus Blue Jackets, while other teams have an elite veteran who is capable of guiding a young apprentice, like Drew Doughty of the Los Angeles Kings or Zdeno Chara of the Boston Bruins. Some teams have been hit with so many injuries that they are left with few alternatives, like the Vancouver Canucks.
Here's a ranking of the eight rookie defensemen being used on the top unit this season, and how they have fared so far:
1. Zach Werenski, Columbus Blue Jackets
Age: 19 | GP: 27 | Pts: 18 | ATOI: 21:49
Werenski was named the NHL's top rookie for November, which is pretty amazing when you consider the competition.
Drafted eighth overall in 2015, and scoring 14 points in 17 AHL playoff games for the Lake Erie Monsters last season, Werenski is the one rookie defenseman who was expected to break out immediately. He leads that group with six goals, 76 shots, and 18 points, thanks in part to nine points on the power play.
Werenski, 19, and Seth Jones, 22, have combined to form what has the potential to be the best pairing in franchise history and have played a key role in the team's surprising 18-5-4 start this season by tilting the ice in favor of Columbus. The Blue Jackets have outshot opponents 454 attempts to 392 with Werenski on the ice, for a plus-62 SAT (Corsi) that ranks third on the team, and a SAT percentage of 53.7 percent that ranks second among rookie defensemen to Edmonton's Matt Benning, who is at 56.9 percent.
2. Nikita Zaitsev, Toronto Maple Leafs
Age: 25 | GP: 28 | Pts: 10 | ATOI: 22:03
Despite being a rookie, Zaitsev may actually be the most seasoned defenseman in Toronto's top four. Prior to making his NHL debut this season, Zaitsev spent seven seasons in the KHL, including four as a top-pairing defenseman, and the last two as one of the league's very best, skating for CSKA Moscow. He also represented Russia in the 2016 World Cup of Hockey and would be a suitable top-four defenseman even on a team with far more blue-line options than the Maple Leafs.
Zaitsev, 25, has scored 10 points in 28 games while playing on the top pair with Morgan Rielly, 22. He is also a secondary choice on the power play, where he averages 2:02 minutes per game, and while killing penalties, 1:22.
Things may not be going perfectly for Toronto this season, but they'd be going a lot worse with one fewer capable two-way defenseman like Zaitsev.
3. Brandon Carlo, Boston Bruins
Age: 20 | GP: 31 | Pts: 7 | ATOI: 22:32
When Zdeno Chara played his first NHL game on Nov. 19, 1997, his current defensive partner Brandon Carlo was still a week away from celebrating his first birthday.
Drafted with the pick acquired from the New York Islanders in the Johnny Boychuk trade, Carlo spent the last three seasons with the Tri-City Americans of the WHL and had just seven games of pro experience in the AHL before suiting up for Boston.
At 6-foot-5, Carlo forms an imposing top pairing with Boston's captain, who stands 6-foot-9. The confidence that coach Claude Julien has in Carlo's defensive skills has resulted in the lowest offensive zone start percentage among Bruins blueliners, 46.6 percent, and an average of 3:11 minutes of shorthanded ice time per game.
Despite that defensive-minded assignment, Carlo has scored seven points in 31 games, and leads rookie defensemen with a plus-7, tied with Detroit's Xavier Ouellet.
4. Troy Stecher, Vancouver Canucks
Age: 22 | GP: 21 | Pts: 7 | ATOI: 21:06
The biggest surprise on this list is Vancouver's undrafted 5-foot-10 defenseman, Troy Stecher.
Initially starting the season with the AHL's Utica Comets, where he enjoyed his first four games of pro hockey, Stecher got an opportunity to play on Vancouver's top pairing with Alexander Edler thanks to an injury to Chris Tanev. Injuries would then strike Edler, paving the way for another rookie on the depth pairing, Nikita Tryamkin.
Stecher is the silver lining to Vancouver's bad luck. He has responded with seven points in 21 games, which is one point back of Ben Hutton for the lead among the team's defensemen, among which he's first in SAT percentage, at 50.5 percent.
Though rarely relied upon to kill penalties, Stecher averages three minutes per game on the power play, and his offensive acumen is helping to keep the Canucks within four points of a playoff spot in a season in which almost nothing is going right.
5. Ivan Provorov, Philadelphia Flyers
Age: 19 | GP: 32 | Pts: 14 | ATOI: 20:46
The Flyers have a nine-game winning streak since coach Dave Hakstol moved Provorov up to the top pairing (the streak stands at 10 games overall), and it is hard to argue with those results.
Drafted seventh overall, immediately ahead of Werenski, in 2015, Provorov scored 73 points in 62 games for the WHL's Brandon Wheat Kings last season and has scored 14 points in 32 games in the NHL this season, which is tied for second among rookie defensemen with Brady Skjei of the New York Rangers. A complete, two-way defender, the 19-year-old Russian has also been trusted with an average of 2:41 minutes per game killing penalties, along with 1:49 minutes per game on the power play.
Provorov and Shayne Gostibehere, who was runner-up for the Calder trophy in 2015-16, are starting to give the Flyers a reputation for finding and developing exceptional rookie defensemen.
6. Josh Morrissey, Winnipeg Jets
Age: 21 | GP: 33 | Pts: 5 | ATOI: 18:35
Due to a contractual issue with Jacob Trouba, an injury to Tyler Myers and his own fine play, Morrissey has spent virtually the entire season on Winnipeg's top pairing with Dustin Byfuglien.
Morrissey, 21, was drafted in the first round in 2013, scored 22 points in 57 games for the AHL's Manitoba Moose last season and has five points in 33 games so far with the Jets -- which includes one scoreless game last season.
Used primarily in an offensive capacity and only at even strength, Morrissey's SAT of plus-37 and his SAT percentage of 52.0 percent both lead Jets defensemen. Yes, Morrissey may eventually slide down the depth chart, but it won't happen while he remains this effective.
7. Derek Forbort, Los Angeles Kings
Age: 24 | GP: 28 | Pts: 9 | ATOI: 18:07
One of the advantages of having an elite defenseman like last season's Norris trophy winner Drew Doughty is that virtually anyone can be used alongside him on the top pairing, allowing coach Darryl Sutter to use Jake Muzzin and Alex Martinez to craft an exceptional second pairing.
Like Brayden McNabb in 2015-16, this season's winner of the Los Angeles linemate lottery is rookie Derek Forbort, 24. The gritty 6-foot-4 defenseman has also been effective on the penalty kill. He ranks fourth among rookie defensemen with 57 hits and first with 34 penalty minutes. Surprisingly, the hard-hitting defender has also contributed nine points in 28 games.
Forbort's shot-based metrics reveal the downside of his game. The Kings have been outshot 381 attempts to 353 with him on the ice at 5-on-5, for an SAT of minus-28 that ranks last on the team since Teddy Purcell, minus-29, was sent to the Ontario Reign of the AHL in early December.
8. Esa Lindell, Dallas Stars
Age: 22 | GP: 22 | Pts: 4 | ATOI: 19:38
Having lost free agents Alex Goligoski, Kris Russell, and Jason Demers this summer, it was obvious that one of the Stars' many rookies would have to step forward to play on the top pairing with John Klingberg. Despite initially being scratched for four straight games and then sent down to the Texas Stars of the AHL, that player eventually proved to be Lindell.
Lindell is an offense-oriented defenseman who scored 42 points in 73 games for Texas last season and led all defensemen in Finland's top league with 35 points in 57 games in 2014-15. Despite this, the 22-year-old defenseman has been used primarily on the penalty kill, rather than the power play, and has only four points in 22 games so far this season.
Like Forbort, Lindell's shot-based metrics are not the greatest; the team's share of all shot attempts drops from 52.8 percent to 46.7 percent when he is on the ice.
Even with the additions of free agent Dan Hamhuis and rookies like Lindell and Stephen Johns, the Stars' blue line has simply been too badly depleted in the summer to compete in the competitive Central division so far this season.