Here is everything you need to know about the term magic number and where it orginated from.
MLB postseason runs have become synonymous with the term "magic number" over the years.
It seems pretty straightforward, but there is a little more that goes into this than you would think. Magic numbers are not just about wins and losses but combined together in relation to another team in question. Basically, a magic number is the number of combined wins and losses a leading team needs over another to clinch something of significance, like a division title or wild card berth.
The exact formula for MLB magic numbers is as follows:
* Games remaining +1 - (Losses by second place team - losses by first place team)
As far as where the term first originated from, it is a little more interesting than just baseball math...
MLB: What is a magic number and where does that term come from?
Apparently, the term "magic number" first surfaced in a 1947 Washington Post article about the AL pennant race between the Boston Red Sox and the New York Yankees. Here is the snippet from the Sept. 12, 1947 article from The Washington Post in question.
"The Yankees reduced the magic number to four. That is the combination of games the Yankees must win or the Red Sox must lose in order to insure the flag for the Yankees."
For this term to have had staying power for a lifetime, it needed to attach itself to two major brands. Fortunately, the Red Sox and Yankees have long been pillars of MLB. While nobody could have foreseen this in 1947, but MLB expansion in the 1960s and 1990s gave birth to divisions and wild card playoff berths. Instead of one team making the postseason out of each league, we now have six.
Technically, you could implement the practice of a magic number as soon as Opening Day, but that would just be patently stupid. We typically start seeing magic numbers arise in the latter part of August, and most certainly throughout September. They gain more and more gravitas as the season winds down. When it comes down to the final week of the season, it is all about magic numbers, dawg.
So when you come across the term between now and early October, now you have been informed.