How MLB teams calculate their magic number for the playoffs

Understanding the MLB postseason race

As the Major League Baseball regular season comes to an end, fans and teams closely watch what is called the magic number. This number tells us how close a team is to securing a spot in the playoffs. It can show how close a team is to winning their division or grabbing a wild card spot.

Basically, the magic number represents the exact combination of wins by that team and losses by their closest rival needed to mathematically guarantee a playoff spot. Every time the leading team wins, the magic number goes down by one. Every time the closest competitor loses, the number also drops by one.

The math behind the magic number

There are two simple ways to calculate this magic number. The first formula is 163 minus the sum of the playoff team's wins and the trailing team's losses.

The second formula uses the number of games remaining. You take the games remaining, add one, and then subtract the difference between the losses of the second place team and the first place team.

For example, imagine Team A has 87 wins and 69 losses with six games left in the 162 game regular season. Team B has 84 wins and 72 losses, trailing Team A by three games. To find Team A's magic number to eliminate Team B, you do 163 minus the sum of 87 and 72, which equals four. Alternatively, you can calculate seven minus the difference between 72 and 69, which also gives you four. This means any combination of four wins by Team A and losses by Team B will guarantee Team A a playoff spot.

The history of the term

The term magic number is not new. Its first known use goes back to September 12, 1947, during a pennant race between the New York Yankees and the Boston Red Sox.

An article in The Washington Post explained that the Yankees had reduced their magic number to four. The newspaper wrote that this was the combination of games the Yankees must win or the Red Sox must lose in order to insure the flag for the Yankees. Today, the term remains a major part of how baseball fans track the final weeks of the season.