The 2009 NHL All-Star Game at the Bell Centre in Montreal
The NHL All-Star Game is held in arenas across the league, which usually seat up to about 20,000 people.
However, the Winter Classic is a whole different animal. It is held in stadiums that can seat double the people a typical NHL arena can.
Take a look at the capacities of the last three All-Star Games against the last three Winter Classics:
Winter Classic Venue Capacities
Ralph Wilson Stadium (2008): 73,967
Wrigley Field (2009): 42,157
Fenway Park (2010): 36,974
All-Star Game Venue Capacities
American Airlines Center (2007): 18,584
Philips Arena (2008): 18,545
Bell Centre (2009): 21,273
While NHL fans are constantly comparing and contrasting the various teams' home buildings, nothing beats sitting among as many as 70,000 other hardcore fans taking in a game. There is often more festivities and more intensity in the air.
Furthermore, the NHL loves making money and setting attendance records and an outdoor game is more likely to do that than an indoor game, for obvious reasons.
However, every venue is unique in its own way, and the opportunity to go to a place that you've never been before is always exciting.