- The Houston Astros won 21 of 27 games in the month of September, best in baseball.
- Houston's opponent in the ALDS, the Cleveland Indians, went 14-14 in the last month of the season.
- Historically, teams that enter the MLB Playoffs on a hot streak haven't performed better than those playing badly.
The Houston Astros finished the regular season winning 21 of 27 games. The hot September run helped the defending champions win 103 games, a franchise record.
The Astros head into the postseason trending in the right direction, but Houston’s opponent in the ALDS can’t say the same. The Cleveland Indians are the only 2018 MLB playoff participant to not have a winning record in September.
The Tribe played .500 baseball to close out the season.
If you believe in clichés, it’s not the best team that wins the World Series but the team that gets hot at the right time. Does a team’s performance in the final month of the season correlate to postseason success?
Using a team’s record in September (plus any regular-season game played in October), we checked the hottest and coldest teams entering the playoffs since the wild card expanded to two teams in 2012. That gives us a sample of 60 teams and 214 playoff games.
The 30 hottest teams entering the postseason had a combined record of 568-292 (.660) over the final month of the season. That is equivalent to this year’s Boston Red Sox, who won 108 games and are the favorites to win the World Series.
On the other end of the spectrum, the 30 coldest teams slid into the postseason with a 451-418 (.519) record. How did the hot and cold teams perform in the postseason?
The hot teams compiled a 109-114 (.489) record, a steep decline from the level of play at the end of the season. The cold teams fared better, going 105-100 (.512).
Even looking at the 10 best and worst teams heading into the playoffs doesn’t change the outcome. The 10 teams with the best record won 72.4% of games in the last month of the season but managed just a 48.1% win rate in the postseason.
The 10 worst teams had a 45.8% win rate ahead of the playoffs, but when October rolled around, their win rate jumped to 54.5%.
Houston is playing its best baseball heading into October, and Cleveland looks destined for an early exit. But the way a team finishes the regular season doesn’t say much about its playoff chances.