Stop me if you've heard this before: "The team that wins the World Series is the one that happens to get hot at the right time." Or "it's not how you start, it's how you finish." Actually, don't stop me. Keep reading. Has this been the case in recent history in the Major Leagues?
Now of course, the team that wins the World Series is the "hottest" team in baseball within the postseason. If they weren't, they would win less than someone else in the playoffs and wouldn't win the World Series. Looking at that seems to be a pointless endeavor. However, what about in the last month of the regular season? Do teams that win the World Series have a better September record than the other teams in the playoffs? All of the conclusions will be drawn from data from the past 13 years.
This chart looks at the winning percentage only in each respective month. The World Series winners perform at basically their true-talent level in September. The hottest teams in September on average don't even make it to the World Series. The coldest teams make it to the World Series, but lose.
If we just look at the difference between the average season winning percentage and the average September winning percentage, the same trend appears. Perhaps the hottest teams are able to ride their winning streak up until the championship series. But that's where it usually ends. The coldest teams ride their losing streak...to the World Series. The World Series winners tend to stay pretty consistent throughout September.
This chart looks at the actual winning percentage for a team at the end of each month. Interestingly enough, on average, the two best teams make the world series. Even more interesting, the World Series losers have a slightly higher winning percentage than the World Series winners.
While it is possible that the definition of "hottest" team only applies to the last few weeks of the season, I unfortunately do not have the data for that. But, just by looking at data since 1995, there is no relationship between having a better September winning percentage than everyone else and winning the World Series. However, recent World Series winners have had great Aprils an Mays, on average. Apparently, it's not how you finish, it's how you start.