Now how does the end-of-April performance tie into making the playoffs or even being a winning team? From 2000-2018 there were 108 teams that ended April with a winning percentage of 40 percent or less, and eight of those teams made it to the playoffs. That means that a team under 40 percent at the end of April has a 7.4 percent chance of making the playoffs. As for teams that started truly terribly, not a single team made the playoffs from 2000-2018 with a winning percentage under 30 percent through April.
In this category are a couple of prime candidates who lost their division in April. The 2005 Cleveland Indians and 2016 Houston Astros seem to be the best examples in the 21st century.
That Cleveland team, who put a strong scare in the 2005 World Series champion White Sox, won 60.4 percent of their games after April. They are actually the only team since 2000 to win 60 percent or more of their games after April and not make the playoffs. How did this happen? Well, Cleveland was 9-14 at the end of April, putting them already 7.5 games behind the White Sox. That April truly did lose Cleveland that division.
As for that 2016 Astros team, they started the season 7-17. That is the 20th-worst start in this entire data set. After April, the Astros maintained a 77-61 record (a 55.8 percent winning percentage). That win percentage would be 90 wins over the course of a full season. Most 90-win teams make the playoffs and, if they had reached 90 wins, the Astros would have made the playoffs with a chance to host a home Wild Card game. This team didn’t lose a division in April, but they may have lost a playoff spot during the first month of the season.
On the other hand, teams can dream at the end of April. Of the 17 teams to win at least 70 percent of their April games, six failed to make the playoffs. Only one team has managed to win 70 percent of their April games, win more than half of their games after April and still miss the playoffs. That team? The 2006 White Sox.
End-of-April performance doesn’t seem to have a big impact on postseason success either. Two teams that ended April with a losing record went on to win the World Series. It actually happened in back-to-back years when the 2002 Anaheim Angels and the 2003 Florida Marlins both accomplished this strange feat.