A friend of mine with advanced degrees in math and economics once got a job on spec with a fantasy sports company that will remain nameless, an outfit that desperately wanted an answer to something that stumped it. This company was curious enough to throw my friend some under-the-table cash to work on its vanity project, a question it assumed had a solution, if only it could find a mystery formula.



His assignment was simple: Come up with a Sports Theory of Everything. What the company wanted was a way to compare the accomplishments and relative value of athletes across all sports and eras. It wanted to pit Muhammad Ali against Joe Montana. Who was “better”?



My friend dove in. He worked off a premise that seemed within grasp. Baseball fans had already discovered a nifty method for comparing players and pitchers across eras, even if they never faced each other. Wins Above Replacement was just that, a way to determine the drop-off if one player was replaced...