The regular season starts in the beginning of April with each team playing a total of 162 games including Interleague play.
The number of games is flexibly set on taking performance/show/entertainment into consideration by the office of Major Leagues.
Generally, teams in the same league and same division compete against each other more times than those of the same league and different division.
For example, a team plays 76 games in their same division while it plays against a team in 2 other divisions, about 66 games (30 – 40 games per division). As 20 Interleague games have been added to this, the total number of games became 162.