The Major League Baseball regular season consists of 162 games per team. That is not including any post season play. As of 2016, there are talks of shortening the season to a possible 154-game season.
In a regular 162 game season, there are a total of 2430 games played from the first week of April to the last days of September. That number may vary due to tiebreakers or games postponed due to weather.
In 2016, the commissioner began talks about shortening the season but were shut down due to owners not willing to lose profitable home games during the regular season. To win the World Series, a team must win 11 games, 12 if they are a wild card, to add to the minimal amount of games in the post season.
The current Major League Baseball Collective Bargaining Agreement calls for each big league club to play a 162-game regular season within a 183-day time period.
Then, leagues started expanding. In 1961, the American League added the Los Angeles Angels and the Washington Senators. The following year, the National League welcomed the New York Mets and the Houston Colt .45’s. “After the first expansion, each team had nine rivals rather than seven, and the 154-game season made for bad math,” MLB’s official historian, John Thorn, explains. To play 22 games against each rival would require a 198-game season, so MLB settled on 18 games per rival for nine rivals, for a total of 162 games.
(Thorn clarifies that yes, in 1961, after the AL had expanded but the NL had not, the leagues played seasons of different lengths. “Both World Series contestants opened their regular seasons on April 11 and concluded on October 1,” he says. “NL had more days off.”)
The season has been 162 games ever since, but it’s taken some work to keep it there. “Even with further expansions, 162 became the de facto standard, and you had to get more and more complicated arithmetically to make it work,” Thorn says. “So when we went to two 6-team divisions [per league] in 1969 the—I think brilliant— the solution was to have more games against the teams in your division, thus enabling you to preserve the 162-game season.”
The addition of the third division in each league in 1994, the introduction of interleague-play in 1997, a final expansion to 30 teams total in 1998 and, most recently, the realignment of the leagues that necessitated perpetual interleague games last season has made for increasingly complicated scheduling and yet the season holds at 162 games.