Recent baseball wisdom holds that wild-card teams can be more successful in the post-season than their division winning counterparts because they are usually the hotter team right at the end of the season. And, since more teams can be involved in a wild-card race than a division race, the team with the latest hot streak usually wins the wild-card. I've been thinking about wild-card teams a lot in the past several years, so I decided to do a study of wild-card teams in the post-season. The results were interesting.
There have been 18 post-seasons in the wild-card era; 1995-2012 (the strike in 1994 eliminated the first post-season with the wild-card format), with one wild-card team from each league. That totals 36 wild-card teams. For the sake of clarity, I'm only counting the wild-card team that won the one-game play-in for the 2012 season.
Overall, wild-card teams have won 34 post-season series and lost 31, for a .523 winning percentage of series. In the NL, the results have been even better: wild-card teams have a 20-15 series record, for a .571 winning percentage. If the Cardinals had won either of games 5, 6 or 7 against the Giants in the NLCS last year, that record would be 21-14, or a .600 winning percentage.
NL wild-card teams have fared better than AL teams overall, with NL teams going 10-8 in the NLDS compared to 9-9 for AL wild-cards in the ALDS. Those NL teams that make the NLCS have won a startling 70% of those, compared to only 33% in the AL. Wild-card teams have ten World Series appearances, winning 5 and losing five. The NL teams are 3-4 in the WS and AL teams are 2-1. One year, 2002, saw the two wild-card teams facing each other in the WS.
Looking at the data I compiled, it does seem true that the wild-card teams have an advantage in the post-season.