Picture it: Game One of the Stanley Cup 2008, almost exactly one year ago today. The Penguins and the Red Wings line up to take the opening face-off. Suddenly Marian Hossa removes his Penguins jersey, puts on a Red Wings jersey, and crosses over to Detroit's side. Historically, the Red Wings won the series in six games, outscoring Pittsburgh 17-10, but how might things have changed with Hossa suiting up for Detroit? As unusual as this situation sounds, it's not far removed from where we find ourselves today.
To determine what kind of impact Hossa's defection would have had, we'll use GVT, or Goals Versus Threshold. Tom Awad developed GVT in 2001 to determine how much (in goals) a player contributes both offensively and defensively compared to a given threshold that represents how well a replacement-level player would perform in the same situation. It's based on goals, assists, plus/minus relative to teammates, goals and shots against, all weighted based on special teams ice time. In Hossa's case, his presence in Pittsburgh's lineup last season meant a 0.14 increase in scoring per game, and only a negligible difference in goals against.
For Detroit, Hossa's presence has meant much more. Fitting in with talented forwards like Pavel Datsyuk, Tomas Holmstrom, Henrik Zetterberg, and Johan Franzen, and receiving crisp passes from Nicklas Lidstrom, Brian Rafalski, and Niklas Kronwall has meant that his presence added 0.19 goals per game of offense to the mighty Red Wings lineup. His surprisingly superb defensive play meant 0.08 fewer goals against as well, meaning that Hossa alone adds up to a 0.41 goals-per-game swing in Detroit's favor. Needless to say, not too many players would have that profound an impact when switching sides.
To explain the difference in value Hossa had for Pittsburgh last season (0.14 net goals-per-game) compared with Detroit this season (0.27 net goals-per-game) we can take advantage of Gabriel Desjardins' Quality of Teammates (QUALTEAM) measurement. QUALTEAM is based on the plus/minus of the linemates a player finds himself on the ice with, and Marian Hossa wound up with the sixth-best score in the league. This means that only five NHL players this season were fortunate enough to play with more talented linemates than Hossa. Compare that to 2007-08, when Hossa spent most of the season with linemates closer to the league-average both in Atlanta, and then initially with Jordan Staal upon joining the Penguins.
Of course, Hossa didn't leave behind a vacuum in Pittsburgh. The Penguins filled the void left by Hossa, as well as others like Ryan Malone, Ryan Whitney, and a host of checking line players that includes Jarkko Ruutu, Adam Hall, Georges Laraque and Gary Roberts with key acquisitions like Bill Guerin, Chris Kunitz, Ruslan Fedotenko, Miroslav Satan, Philippe Boucher, Matt Cooke, Mark Eaton, and Craig Adams.
Other than adding Hossa, the Red Wings line-up has barely changed at all. Their only changes are among the depth players, losing Dallas Drake and Andreas Lilja (to injury), but gaining Jonathan Ericsson, Justin Abdelkader, Derek Meech, Ville Leino, and Tomas Kopecky. For Detroit, the biggest difference from last season is a general decline in most of their starting players, especially defensively.
Factor DetG PitG Swing
Decline in Detroit's play -0.17 +0.51 0.68 Pittsburgh
Marian Hossa +0.19 -0.22 0.41 Detroit
Pittsburgh's other personnel changes -0.11 +0.15 0.26 Pittsburgh
Improvement in Pittsburgh's play -0.14 +0.06 0.20 Pittsburgh
Detroit's other personnel changes +0.05 0.00 0.05 Detroit
TOTAL -0.18 +0.50 0.68 Pittsburgh
The only factor larger than the Hossa factor is the decline in Detroit's play, which should mean a 0.68 goal-per-game swing in Pittsburgh's favor. The Penguins are not facing the best defensive team in the league as they did last year, who gave up a paltry 2.18 goals per game in the regular season. Instead they're playing a team that gave up 2.93 goals per game, one where last year's more dominant defensive players like Henrik Zetterberg, Dan Cleary, Mikael Samuelsson, and Brian Rafalski have become mere mortals.
If that didn't eliminate Detroit's advantage, their ultimate nightmare scenario will. Detroit has a few players working through injuries, and if they should be serious enough to keep players like Nicklas Lidstrom and Pavel Datsyuk out of the line-up, the consequences could add up to another half-goal swing in Pittsburgh's favor:
Factor DetG PitG Swing
Detroit's potential injuries -0.33 +0.19 0.52 Pittsburgh
NIGHTMARE SCENARIO TOTAL -0.51 +0.69 1.20 Pittsburgh
While these statistics are based on the regular season in order to avoid the skewing effects of the small sample size and limited number of opponents in the playoffs, we shouldn't completely ignore the patterns we've seen so far in the post-season. Sidney Crosby and Evgeni Malkin, for instance, are scoring at an incredible pace, with 56 points in 17 games. Detroit may have overachievers like Chris Osgood, Johan Franzen, and Dan Cleary, but you also have to weigh it against the decreased scoring from Tomas Holmstrom and Pavel Datsyuk, who have combined for only 12 points.
Detroit convincingly defeated Pittsburgh in last year's NHL Stanley Cup Final, outscoring them 17-10 in 6 games. Given the decline in Detroit's play and the possibility of some key injuries that 1.2 goal-per-game advantage would completely disappear without the Hossa Factor. All other things remaining equal, Marian Hossa is the key statistical difference-maker, and the primary reason why the Red Wings are favored to repeat as Stanley Cup champions in 2009.
A version of this story originally appeared on ESPN Insider .
Robert Vollman is an author of Hockey Prospectus.
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