The American League and National League have been a part of Major League Baseball for a great portion of its history, but expansion could risk their extinction.

When MLB expansion comes up, which cities will get new teams is always the first topic. But there's another factor that will impact the entire sport: How will MLB realign its divisions -- and structure its playoffs -- to accommodate those new franchises.

Geographic realignment in MLB is more likely than you think. Or, more likely than previously thought, after commissioner Rob Manfred surprisingly discussed the subject on Sunday. With expansion expected before the end of this decade,