No matter how good a team may be in the regular season or how blazing hot they get down the stretch, one nice thing about being an NHL fan is there is enough parity in the league that every team feels it has a chance come playoff time. On the other side of that coin, every fan base is also nervous heading into the postseason because there are no perfect teams.
With that said, let's have a look at one key weakness that each of the clubs currently in playoff position -- along with those still in the race -- will either have to correct as they head into the playoffs, or that could derail a trip to the Stanley Cup Final.
Atlantic Division
Tampa Bay Lightning
Kryptonite: Penalty kill
Key stat: 26th in penalty kill percentage
With the addition of Ryan McDonagh at the deadline, there isn't a clear weakness on Tampa Bay's roster. The Lightning are the best scoring team in the NHL, led by two of the premier players in the league, Steven Stamkos and Nikita Kucherov. They now have a stacked blue line led by 2016-17 Norris Trophy finalist Victor Hedman, and have received quality goaltending from Andrei Vasilevskiy (.923 save percentage).
Tampa Bay has enough firepower to overcome struggles on the penalty kill, but especially in the early rounds, there is always the possibility of special teams swinging a series.
Boston Bruins
Kryptonite: Tuukka Rask's recent slide
Key stat: .904 save percentage over the past two months
The B's are an elite team in nearly every category, ranking second in Corsi for percentage, sixth in goal scoring rate at even strength and fifth in power-play percentage. But Rask's recent play could be cause for concern. His second half of the season hasn't been nearly as impressive as his start, and during the past three seasons he's merely been an average goalie, with a .916 save percentage. You might've heard that goaltending is important in the Stanley Cup playoffs.
Toronto Maple Leafs
Kryptonite: The blue line
Key stat: Eighth most shot attempts allowed per 60 minutes at even strength
Toronto has offensive firepower that rivals the best teams in the NHL, but they are heavily reliant on goaltending on the defensive end. The Maple Leafs did not upgrade their blue line at the deadline, and will head into the postseason asking 36-year-old Ron Hainsey to play 22 minutes per game.
Florida Panthers
Kryptonite: Scoring beyond their top lines
Key stat: 56.8 percent goals for percentage when Aleksander Barkov, Jonathan Huberdeau and Evgenii Dadonov are on the ice together
After a rough start to the season, the Panthers have gone on a crazy-hot run down the stretch (including going 8-1-1 in their past 10). Florida has been fueled by a rejuvenated Roberto Luongo, who has a .926 save percentage and has given the Cats a quality start (under three goals or over a .916 save percentage) in 65.4 percent of his starts. Whether they can ride hot goaltending and a tremendous top line long enough to get into the playoffs is yet to be seen.
Florida's top line could make them a contender in the postseason, but when they are off the ice, the team's goals for percentage drops by 12 percent.
Metropolitan Division
Washington Capitals
Kryptonite: Protecting the net front
Key stat: 13.0 high-danger shots per 60 minutes at even strength, second most allowed in the NHL
Alex Ovechkin's brilliant season has driven Washington to the top of the division, but the Capitals have some noticeable deficiencies on defense. They give up the sixth-most shot attempts per 60 minutes at even strength, and far too many shots in close areas. The defensive struggles may be playing a role in Braden Holtby's struggles this season.
Pittsburgh Penguins
Kryptonite: Goaltending
Key stat: 31st in the NHL in even-strength save percentage
Normally when a team is dead last in even-strength save percentage, they miss the playoffs by a wide margin. The Penguins aren't a normal team. Despite Matt Murray's injuries and inconsistency and the lack of a proven backup, Sidney Crosby, Evgeni Malkin and Phil Kessel have kept Pittsburgh alive. If Murray returns and rises to the challenge in the postseason as he has the past two years, the Pens could be raising their third Stanley Cup in a row.
Philadelphia Flyers
Kryptonite: High-paced game
Key stat: Sixth-fewest shot attempts for, fourth fewest against per 60 minutes at even strength
They may have hit some bumps in the road this season -- including an 0-5-5 stretch -- but a breakout season from Sean Couturier and the rise of young blueliner Ivan Provorov have helped make the Flyers a contender. However, Philly has only been a so-so even-strength team, ranking 16th in even-strength goals for percentage. They could be in trouble if a series turns into a track meet.
Columbus Blue Jackets
Kryptonite: Special teams struggles
Key stat: 29th-ranked power play, 24th-ranked penalty kill
The Blue Jackets could very well be a dangerous playoff team. At even strength, they put the third-most shots on goal per 60 minutes in the NHL and have a Vezina Trophy-winning goaltender. Columbus has also been blazing hot, going 8-2-0 in their past 10 games. But if the Jackets can't figure out how to score on the man advantage -- and slow down opponents' power plays -- they won't be making a deep postseason run.
New Jersey Devils
Kryptonite: Lack of a top-notch defensive pairing
Key stat: 21st in scoring chances allowed per 60 (per Natural Stat Trick)
These aren't your mother and father's New Jersey Devils, nor even your older sibling's. They are fast, exciting -- and struggle to slow down opponents' offensive attacks. Not only are the Devils giving up a high rate of scoring chances, goalie Cory Schneider isn't bailing them out. New Jersey ranks 27th in even-strength save percentage. Teams rarely win in the NHL on offensive prowess alone.
Central Division
Nashville Predators
Kryptonite: Lack of an elite two-way center
Key stat: 46.9 percent high-danger shot percentage with Ryan Johansen on ice at even strength
Nashville has a deep group of forwards, arguably the NHL's best blue line and a goaltender playing the best hockey of his career. All the ingredients for a return to the Stanley Cup Final are there, and the numbers back it up: the Preds are No. 1 in the West in goals for percentage at even strength.
The only concern is that opponents might try to match up scorers against Johansen in a seven-game series. The last 10 Cups have been won by teams with elite two-way centers like Sidney Crosby, Jonathan Toews, Anze Kopitar, Patrice Bergeron and Pavel Datsyuk.
Winnipeg Jets
Kryptonite: Unproven goaltending
Key stat: .907 save percentage for Connor Hellebuyck in 2016-17
The addition of Paul Stastny may have made the Jets the most complete team in the NHL. In all situations, they are fourth in goals scored and goals against, and top five in both areas of special teams. Winnipeg seems destined for a deep run. The only question is their young goaltender, who has been fantastic this season, posting a .925 save percentage, but sputtered in 56 starts last season. If the 2017-18 version of Hellebuyck shows up in the playoffs, watch out West.
Minnesota Wild
Kryptonite: Playing on the road
Key stat: 15-18-1 away from Xcel Energy Center
It's tough to explain why the Wild have been so poor away from home, but if Bruce Boudreau's bunch plans on bucking Minnesota's trend of first-round outs, they will have to win big games on the road. First, of course, the Wild will have to get in the postseason. They currently sit two points up on Dallas for the final spot and just lost top-notch defenseman Jared Spurgeon for up to a month with an injury. Seven of their final 12 games are on the road.
Dallas Stars
Kryptonite: Inconsistency
Key stat: 5-6-3 since a five-game win streak in February
When the Stars are hot, they are unstoppable. Ken Hitchcock has turned around their defensive play this season, pushing Dallas up the defensive ranks to fifth in even-strength goals allowed per 60 minutes. Scoring has not come as easy despite a tremendous season from Tyler Seguin and Alexander Radulov. Hitchcock's bunch will have to find the good version soon or they will lose their one-point lead over Anaheim for the final wild-card spot.
Colorado Avalanche
Kryptonite: Leaky defense
Key stat: 28th in shot attempts allowed per 60 minutes at even strength
No longer are the Avs a nice story; they are a legitimate contender. Nathan MacKinnon has made a strong case for the Hart Trophy, with 82 points in 61 games, and Mikko Rantanen appears to be a star on the rise. Those two players would not be fun to match up with for seven games. But if they give up oodles of shots and chances to a highly skilled Western team like Nashville, Vegas or Winnipeg, Colorado's season will quickly come to an end.
St. Louis Blues
Kryptonite: Shortage of goal scoring
Key stat: 30th in goals scored per game
Ranking in the basement in even-strength scoring and 24th on the power play, it's surprising the Blues are even still in the playoff conversation. With their defensive prowess, St. Louis might be a club that could be tougher in the postseason. They rank sixth in shot attempts allowed and fourth in goals allowed at 5-on-5. But time is running out for Mike Yeo's group to slide into the postseason.
Pacific Division
Vegas Golden Knights
Kryptonite: Goaltending regression
Key stat: Marc-Andre Fleury's 68.3 percent quality start percentage
At the very top of the list of unexpected things this season is Vegas winning its division. There are no flukes on this team. The Golden Knights win the shot counter and have more goals scored than anyone in the West. A big part of their success has been outstanding goaltending. Fleury is currently playing 14 points above his career save percentage and 15 percentage points above his usual quality start percentage. If those numbers don't sustain, it will be an uphill battle for Vegas.
San Jose Sharks
Kryptonite: Reliance on special teams
Key stat: 22nd in goals for percentage at even strength
At 5-on-5, the Sharks have been thoroughly mediocre, but the ninth-best power play and No. 1 penalty kill have guided them into the No. 2 spot in the Pacific. As the playoffs go on, however, things generally tighten up and the best even-strength teams win. It's also hard to see the Sharks' past-its-prime core of stars winning four rounds.
Los Angeles Kings
Kryptonite: Depth scoring
Key stat: Anze Kopitar has 76 points, the next best forward has 46
The top-heavy Kings are thrilled to get Jeff Carter back in the lineup after months out due to injury. The Kings will be clinging to their spot down the stretch, but if they get in, Los Angeles is never out of a playoff series as long as they have an elite No. 1 center, Norris Trophy defenseman in Drew Doughty and proven playoff goalie in Jonathan Quick, who is having his best save percentage season since 2011-12.
Anaheim Ducks
Kryptonite: Reliance on Ryan Getzlaf
Key stat: 3.3 goals per 60 minutes with Getzlaf on ice, 2.1 per 60 when off
A slew of key injuries to Getzlaf, Ryan Kesler and Hampus Lindholm early in the season caused the Ducks to struggle out of the gate. With Getzlaf dominating to the tune of 51 points in 46 games and a plus-5.1 percent relative Corsi, Anaheim is back in the mix. But in the 40 minutes per game during which their veteran superstar center isn't on the ice, Anaheim is a sub-par team. Getzlaf's even-strength scoring rate is just ahead of Evgeni Malkin and a shade behind Connor McDavid, yet his team ranks 21st overall in goal-scoring rate. In order to make noise in the postseason, the Ducks will need players like Andrew Cogliano, Adam Henrique and Jakob Silfverberg to rise to the occasion.
Calgary Flames
Kryptonite: Taking advantage of scoring chances
Key stat: Third in Corsi for percentage, 17th in even-strength scoring
It has been a disappointing season for the Flames, who seemingly have been close to breaking out with young scoring talent and a skilled blue line. Calgary simply hasn't gotten enough scoring outside of Sean Monahan, Johnny Gaudreau and Matthew Tkachuk.