^ Great book.
But seriously, dicky, there are two leagues - the National and American. Each league has 4 teams that advance from the regular season to the playoffs. Those four play in an elimination series (1 vs. 4, 2 vs. 3, winner of 1 vs. 4 vs. winner of 2 vs. 3) to determine who the champion of each league is. The two league champions then compete in the World Series to determine who the WORLD CHAMPIONS (that's right - i said it!) are.
Each league has 3 divisions. The winner from each division is guaranteed a playoff spot. The last spot goes to the team with the best record after the division winners.