The National League West is one of the three divisions of the National League of Major League Baseball in North America (including Canada). This Division was formed for the 1969 season when the National League expanded to 12 teams by adding the San Diego Padres and the Montreal Expos. For purpose of keeping a regular-season of 162 games, half of the teams were put into the new East Division and half into the new West Division. Within each division, the teams played 18 games each against their five division mates (90 games), and also 12 games against the teams in the opposite division (72 games), totaling 162 games.