"Magic numbers" have gotten a lot more difficult to understand in baseball since MLB moved to the two team Wild Card format in 2012.
Here is what a magic number is: the number is the number of wins by the Red Sox and number of losses by opponents needed for the Red Sox to make the playoffs. In other words, the Red Sox' chances of making the postseason are great.
With 12 regular season games left, their magic number for winning the AL East is nine. Their numbers for making the playoffs via the final Wild Card slot is seven.
For reference the Rangers' magic number to wrap up the AL West is three. The Indians' magic number to wrap up the AL Central is seven.
The Sox currently lead the AL East by four games and MLB.com has their odds of a division title set at 91.5 percent. Their postseason odds are 99.8 percent.