As of this writing, the Yankees’ magic number stands at 14. By itself, that magic number doesn’t really tell us too much though about the Yanks’ chances of making the playoffs. After all, they could have a magic number of 14 with 30 games left; they could have a magic number of 14 with, as they do now, 19 games left. In this day and age of exact baseball numbers, the magic number is a relic of another era.
Earlier this week, Walk Like a Sabermetrician proposed an adjustment to the magic number formula. Instead of a pure magic number, WLAS proposes a Magic Percentage. It is “the percentage of game outcomes that must go a team’s way in order for them to clinch. In this case, game outcomes include both the team in question’s games and the games of their opponents.”
He explains further:
Suppose that the race between the Alphas and the Bravos is shaping up like this, with ten games left for each team:
The Alphas’ M# is 9. Again, that means that a combination of nine Alpha wins and Bravo losses will clinch the division. Since each team has ten games left, there are twenty total game outcomes outstanding, and 45% of them (9/20) must go the Alphas’ way. Therefore, their M% is 45%. Since I always feel compelled to write out a formula, here it is:
M% = (M#)/(2*g – W – L – oW – oL)
In other teams, the formula is Magic Number divided by the number of total games left for the first and second place teams. The Yankees have a Magic Percentage of 33. They need only 33 percent of the remaining games to go their way — that is, a Red Sox loss or a Yankee win.
There are some similar problems with Magic Percentage as Magic Number. It still pays to know how many games the team in question has left. But other than running Baseball Prospectus-style Monte Carlo simulations — the latest post-season odds report give the Yanks the East 99.4 percent of the time — this Magic Percentage is a step toward a better magic number.
Here’s your Saturday night open thread. There’s some college football on, some rain-delayed baseball games. You know the drill. Play nice.