The introduction of the wild card in 1994, first used in 1995, changed the post-season baseball forever. Baseball within two years transformed from being a sport where the regular season was grueling and few teams made the relatively brief playoffs to one where a ticket to the post-season was now easier to get, but the playoffs were expanded to look more like other sports. The relative benefits and drawbacks of this playoff system is a subjective matter, but now that there have been 14 seasons using this format, it is possible to reflect on what we have learned about the new playoff system.
Because seeding in the playoffs is based on regular season record under the new system, it is useful to see what seed has generated the most World Series winners. The answer should not come as a surprise. Teams that went on to win the World Series were the best teams in their league in five out of the 14 seasons. No other seed had as many champions. Teams that finished with the second best record in their league went on to win the World Series three times. Thus, more than half of the last 14 World Series were won by teams that either had the first or second best record in their league.
After this the story gets a little more complicated. Two teams won the World Series as the weakest of the three division winners; and four teams won the World Series as the wild card. Interestingly, however, two of the wild card winners had the second best record in their league while the other two had the third best record in their league. Although these championship teams had gotten into the playoffs as the wild card, they were not the weakest playoff teams in those years. The weakest champions, based on record were not wild cards, but the 2006 Cardinals and 2000 Yankees who won their divisions, and the World Series despite having the fifth and fourth best record in their leagues respectively.
Another way to address this question is to look at what happened to each of the 28 wild card winners during the last 14 post-seasons. In any post season, four teams will be eliminated in the LDS, two in the LCS and one in the World Series, leaving one team as the World Series winner. The expected ratio of these outcomes, if they were randomly distributed, would be 4:2:1:1 or, because there have been 28 wild card teams, 14 eliminated in the LCS, seven in the LDS, 3.5 in the World Series with 3.5 winning the World Series.
The actual outcomes are quite similar to what can be expected. Of the 28 wild card teams, 12 were eliminated in the LDS, seven in the LCS, five lost the World Series and four won the World Series. The data show that wild card teams did slightly better than expected over the course of the last fourteen postseasons.
The methodology here is quite crude. I did not explore how other factors such as runs scored, runs allowed, Pythagorean records or anything else might have bearing on what happens to teams in the postseason, but I wanted to look specifically at the fate of wild cards. The universe of wild card teams is also quite small, so projections based on this should be done cautiously.
There are, however, at least two major findings which seem clear. First, and expectedly,at the beginning of any postseason, the teams with the best chance of winning the World Series are the teams which had the best record during the regular season. Five of these teams won the World Series where we would have expected only 3.5, so the difference is small, but real.
Second, and more interestingly, while wild card teams can win, it is only the strongest wild card teams, those with the second or third best record in their league, that win the World Series. Wild card teams that have the fourth, fifth or sixth best record in their league tend to make an early exit from the playoffs and have won no championships.
While some fans will never like the wild card system, the results after the first fourteen years suggest the worst scenario, where mediocre teams sneak into the playoffs as the wild card and go on to win the World Series, has yet to occur. The only two teams that were not among the three best in their league to win the World Series got into the playoffs not due to the wild card, but due to a related problem which came into existence with the wild card, that of small divisions.