« MC Hammer at Techcrunch 20…
Chris DiBona »

X W-L Standings Statistic

Published May 12th, 2007 in Personal, Tech & VC

Update: I found this Wikipedia article about the origins of this X W-L formula. Of course, I should have looked at Wikipedia first…

Original Post: I just learned about the X W-L stat is baseball standings. I don’t know if it’s a common metric for all baseball standings, but they use in at MLB.com.

According to MLB.com, X W-L is the expected number of Wins and Losses based on runs scored (RS) and runs allowed (RA). The following formula is used to calculate X W-L:

RS^1.82/((RS^1.82)+(RA^1.82))

I think this is pretty cool. You can use X W-L as statistical evidence about the luck of a given team. For example, the general buzz around New York is that the Yankees rocky start was due to a lot of close losses, bad luck. Their actual W-L is 16-18 and their X W-L is 19-15, a difference of three games. So, there’s some statistical evidence to the thought that the Yankees are just down on their luck.

I wonder how the MLB derived the 1.82 constant in the X W-L formula? I’m sure there’s a math major out there that understands the greater principle at work here.

3 Responses to “X W-L Standings Statistic”  

Feed for this Entry
  1. 1 Alex Janevski Jun 6th, 2007 at 8:00 pm

    The 1.82 exponent has been experimentally determined. Initially, 2 was used, hence the equation was dubbed the “Pythagorean Expectation” for its similarity to the equation that bears the same name. However, at least for baseball, experiment has shown that 1.82 is more accurate at predicting than 2. As for mathematically why this is the case I have yet to see a good explanation. Likely it involves a somewhat complicated statistical argument. From one paper I’ve seen I’m left with the feeling that it has to do with the actual values of runs scored and runs against in a given season, that is, the distribution of said values around the mean.

    Hope this helps.

  2. 2 Joe Bob May 23rd, 2008 at 9:12 pm

    I think the reason that 1.82 is used in the equation is because of baseball’s magical mathematicians, such as Derek Jeter and Melky Cabrera. Everyone already knows that the people working behind the scenes (like Brian Cashman) are magical

  3. 3 South Side Dave May 29th, 2008 at 7:57 pm

    God I hate the Yankees.

Leave a Reply