I was trying to do that with my opening post. A top five goal differential makes you one of the top teams in the league. Take a look at the standings on nhl.com, switch to see the whole league then sort by goal differential. Every year the top teams have the best goal differential and vice versa. The really nice part is that the to goal differentials are fairly consistent season over season. Tops being right around 60ish and number five being around 45 or so.
This is why I like to look at how many more goals the Kings need to be competitive. An additional 30 goals this past season would have given them the best goal differential in the league. When you look at it that way the Kings really are one elite player short. But with with Vilardi coming up next season replacing a player that scored less than five goals we need only one above average player to make the 30 goal number. We are so much closer than the majority of this board thinks.
See I think of "contenderness" as the ability to challenge for the Stanley Cup, but you're really thinking of it as the ability to challenge for the President's Trophy. Having a top 5 goal differential makes you a good team that will certainly make the playoffs, but it doesn't really tell you who is left standing at the end.
Since the lockout, lots of teams have gone on long runs to the Stanley Cup Finals without a top five goal differential. Those teams are in bold:
2006: Carolina Hurricanes (#4) defeated
Edmonton Oilers (#14)
2007:
Anaheim Ducks (#6) defeated Ottawa Senators (#2)
2008: Detroit Red Wings (#1) defeated Pittsburgh Penguins (#4)
2009:
Pittsburgh Penguins (#9) defeated Detroit Red Wings (#2)
2010: Chicago Blackhawks (#2) defeated
Philadelphia Flyers (#12)
2011:
Boston Bruins (#7) defeated Vancouver Canucks (#1)
2012:
Los Angeles Kings (#11) defeated
New Jersey Devils (#9)
2013: Chicago Blackhawks (#1) defeated Boston Bruins (#5)
2014:
Los Angeles Kings (#7) defeated
New York Rangers (#10)
2015: Chicago Blackhawks (#4) defeated Tampa Bay Lightning (#2)
2016: Pittsburgh Penguins (#2) defeated San Jose Sharks (#5)
2017: Pittsburgh Penguins (#4) defeated
Nashville Predators (#13)
The average goal differential position of the Stanley Cup winner over the past 12 years is 4.8 and the loser is 6.6.
Goal differential is an excellent predictor of whether your team makes the playoffs. If you score more than your opponents over 82 games, you're also likely to win more than your opponents over 82 games. Being that about half the teams make the playoffs, those that have a positive goal differential almost always make the playoffs.
Goal differential, on the other hand, is not a great predictor of whether your team will go far in the playoffs. Just in the list I put up above, 5 out of 12 times the team with the lower goal differential defeated the team with the higher differential.
Therein lies the difficulty with figuring out who's a contender. You can ask the Washington Capitals or the Vancouver Canucks. For years these teams would have a great goal differential and finish atop the standings, yet they rarely broke through to the promised land. You can assemble great teams on paper, but there's something about the playoffs that is hard to quantify. Dean Lombardi put his finger on it for three years, but he's not here anymore.