On Friday, Milwaukee Brewers shortstop Jean Segura performed an act of baserunning lunacy so unforeseeable that play-by-play software couldn’t even process it, says baseball historian David Vincent. ESPN.com offers a detailed account of the bewildering play, in which Segura tried unsuccessfully to steal third, ran back to second (now occupied by teammate Ryan Braun), and seemingly got tagged out before sprinting all the way back and "stealing" first. Later in the inning, Segura tried, unsuccessfully, to steal second, but because the scorekeeping software wasn't equipped to handle the case of a runner going backwards around the bases, the official box score shows Segura being tagged out at third.

"Any software that processes play-by-play won’t accept that."

By all accounts, the play appears to have been perfectly legal, just so incredibly unpredictable that decades of computer programmers never wrote a way to account for it. "You don’t run the bases [from] second to first," said Vincent, a longtime official scorer. "Any software that processes play-by-play won’t accept that." The reason for the deficiency appears to be just that no one has had to consider it before — according to ESPN, there’s no precedent for what Segura did on Friday in 63 seasons of baseball.