The theory is that total goals scored for and against, goals-against averages, and power play opportunities are inconsequential in determining who will raise the Stanley Cup in June.
The Shots on Goal Differential is calculated simply by taking the total number of shots a team takes in a game, and subtracting the number of shots given up. Over the course of a season, it's a decent indicator of how good a team truly is.
Perennial contenders like Detroit have a SOGD approaching +10, which is elite. Teams that are on the downswing (like the Penguins of a few years ago before the NHL lockout), tend to be consistently in the negative.
Looking at last year, the Western Conference teams sent four teams with a positive SOGD and four teams with a negative to the playoffs, and the first round matchups pitted a positive vs. a negative. The positive teams all advanced to round two.
The Eastern Conference didn't shake out so evenly. In fact, three of the four semi-finalists had negative SOGDs. The Penguins had the worst SOGD in the league among all playoff teams, yet they got to the Final.
Therefore, there are still some bugs to be worked out in the theory, although its importance is evident.
There has been no Stanley Cup winner with a negative SOGD since the 1990-91 Penguins, but, in that case, there was a significant mitigating circumstance; at the trade deadline, they shanghaied the Hartford Whalers for the ultimate face-off man in Ronnie Francis and a juggernaut on defense in Ulf Samuelsson.
It's very possible that those Penguins' SOGD was already so far in the negative that even if the Pens were in the positive from the trade deadline on, there wouldn't have been enough time to vault them into the positive.
Last season, the Penguins acquired Marian Hossa, Pascal Dupuis, and Hal Gill at the trade deadline, and that may have made all the difference.
Things could be similar for this year's Penguins.
For the season, the Pens' SOGD is -1.3. They bottomed out somewhere near -4. Since Dan Bylsma took over for Michel Therrien as Penguins head coach on February 15, the Penguins are a +4.4.
Since the trade deadline (March 4), the Penguins are nearly +6.5.
This year's chart displays the seed, the team, its season-long SOGD, and, in parentheses, each playoff qualfier's SOGD after the trade deadline. Negative SOGD are marked in boldface.
1. Boston -0.5 (-1.9)
2. Washington +4.0 (+7.0)
3. New Jersey +3.5 (+4.0)
4. Pittsburgh -1.3 (+6.5)
5. Philadelphia -2.8 (-2.4)
6. Carolina +3.1 (+2.8)
7. NY Rangers +2.7 (+3.7)
8. Montreal -1.7 (-4.3)
9. Florida -5.3
10. Buffalo -0.9
11. Ottawa +0.8
12. Toronto +1.5
13. Atlanta -4.6
14. Tampa Bay -4.4
15. NY Islanders -4.6
1. San Jose +6.0 (+3.1)
2. Detroit +8.4 (+9.0)
3. Vancouver -0.7 (-1.3)
4. Chicago +4.1 (+5.0)
5. Calgary +2.5 (+4.5)
6. St. Louis -0.9 (+0.9)
7. Columbus +1.1 (-1.1)
8. Anaheim -0.2 (+3.3)
9. Minnesota -3.2
10. Nashville -0.4
11. Edmonton -4.5
12. Dallas +0.8
13. Phoenix -3.5
14. Los Angeles +1.0
15. Colorado -0.2
Based on the above, the following two first-round picks could be made with a certain degree of certainty.
- Detroit Red Wings over Columbus Blue Jackets.
Even though Columbus seems to play Detroit tough during the regular season, the defending Stanley Cup champs have an advantage in SOGD of +7.3 (+10.1 since the trade deadline), and they're facing a franchise making its initial trip to the postseason. This is the lock of the first round.
- Pittsburgh Penguins over Philadelphia Flyers.
The East pits season-long negative SOGD against negative and positive vs. positive in an odd coincidence, but the trade deadline difference between these two teams in particular serves as the tie-breaker. Pittsburgh is the clear statistical favorite (+8.9).
All the top seeds in the East should hold serve. The most intriguing series is the New Jersey Devils versus the Carolina Hurricanes. Carolina goaltender Cam Ward is playing on another planet right now. A Hurricane series victory could only be scored as a light upset.
Upset watch in the West: Anaheim Ducks over the San Jose Sharks. Anaheim actually has the SOGD edge since the trade deadline. Home ice advantage may not help the Sharks against a team that won the Cup just two years ago.
The statistic shows that St. Louis may pull the upset over Vancouver, but Canucks netminder Roberto Luongo could be the difference-maker here.
Meanwhile, Chicago and Calgary should be the most entertaining series in the first round.
Long term, it looks like a Detroit/Washington Stanley Cup Final, but the Penguins, the Sharks, or even the Blackhawks or the Flames could crash the "Rematch of 1998".
If the winners don't break out as the SOGD stats spell out, praise will be heaped upon the opposing goalie in direct proportion to how great the differential is between the teams.
In any case, the 2009 Stanley Cup Playoffs should feature more series that go at least six games than last year.