Season Description The 2017 Major League Baseball season began on April 2 with three games, including the 2016 World Series champions Chicago Cubs facing off against the St. Louis Cardinals, the regular season ended in late September. The postseason began on October 3. The World Series began October 24 and Game 7 was played on November 1, in which the Houston Astros defeated the Los Angeles Dodgers in seven games, to capture their first World Series championship in franchise history.