As appears to be the case for many categories of this matchup, there are quite a bit of similarities between both of these teams' blue lines. The narrative following both Nashville and Chicago is these are two teams who have struggled defensively due to a lack of defensive depth but are propelled by superstar defensemen.
Nashville's trade for Cody Franson apparently hasn't worked out, and Seth Jones isn't the premier 19-year old defenseman many want him to be at this point in his career. Chicago's loss of Nick Leddy and pickup of Kimmo Timonen have severely hurt their defensive depth to a point of worry for Chicago fans.
Unfortunately, many of these narratives don't hold up against possession metrics.
Possession Metrics Ordered From Best To Worst SACF%
Score-Adjusted Corsi-For %
Score-Adjusted Relative Corsi-For
|Cody Franson||NSH||23 (w NSH)||56.26%||3.60|
The previous table is ordered from best Score-Adjusted Corsi-for percentage to worst, and there seems to be an interesting dynamic occurring here. Players who apparently can't get the job done - Franson, Jones, and David Rundblad - are putting up some of the best possession numbers on their teams while defensive elites - Roman Josi, Shea Weber, and Brent Seabrook - are actually possessing the puck less than many of their teammates.
Defensive depth is something all teams look to improve, especially heading into the playoffs. Nashville and Chicago both have enough of it to carry them deep into the playoffs, but it may be their top players who need to play better.
Weber, Josi, and Hjalmarsson have faced the toughest competition, but that doesn't necessarily explain their sup-optimal possession metrics. For one, the difference between the toughest competition (Hjalmarsson) and the weakest (Timonen) is only about 1 minute of ice time. Recent analysis has shown that quality of competition is not as significant of a factor for possession as we once thought while zone starts are not an accurate portrayal of player usage as well. Whatever the cause, the lack of possession from some of the superstars on each team would be of greater concern to these teams if they weren't facing the exact same thing in their competition.
Player Usage Chart
There isn't anything entirely awful about each defense. Only Timonen, at 45.45%, is below 50% Score-Adjusted Corsi%. Despite the upside, Chicago has slowly been giving up more and more shots this season while their transition play from the blue line - a strategy that generally gives them dominating success - has fallen off this season. Nashville, on the other hand, has evolved from being a conservative, neutral-zone stifling team to one that prefers to push the pace. Much like Chicago though, this has resulted in a decreased ability to prevent shots against as the season has gone on.
Corsi Against Per 60 (20 Game Moving Average)
As the above graph shows, both teams have followed a similar trend in Corsi Against, improving over the last stretch of games. Although this is a team metric and not confined to just defensemen, the positive trend for each team is something each can build off of despite not translating it to success in the last stretch of games in the regular season.
It's tough to figure out whether Nashville or Chicago has the upper hand on the backend as the similarities between the two teams are more glaring than the differences. If anything, Nashville has a stronger defensive depth with the potential for Chicago to play Rozsival or Timonen over Rundblad.
Ultimately, predictions at this time of year are so hard to get right especially with two teams this evenly matched on defense. It may be more accurate to just flip a coin 100 times to pick a favorite. Just don't be surprised when the odds come up at 50%.