The (dis)honor of the inaugural post in this series goes to Anthony Castrovince (of MLB.com and Sports on Earth), whose most recent column details "13 individuals or entities who, for one reason or another, can claim bad luck without it sounding like a loser's lament." The column itself wasn't so bad, save for a few annoyances like describing FIP as "a measure of the things a pitcher has under his control" (as if a pitcher magically has control over a batted ball outcome if it happens to go over the fence, but not if it lands two feet in front of it), or speaking of balls whose trajectories had the same "exact specifications" without any mention of error size, or (as per usual) quoting Statcast numbers to three significant figures.
Towards the end of the article, however, Castrovince presents us with a real whopper:
(For those readers who don't immediately see why this is abject nonsense: imagine that Adam Jones hit all of his balls at a 94mph exit velocity, but hit half of them at a 52-degree launch angle and the other half at a -28-degree launch angle - a distribution that is, indeed, consistent with his "average trajectory." Using the tool Castrovince links, we should expect Adam Jones to have a BABIP of under .100! The key point here is that the mean does not uniquely specify, or even provide much useful information about, the actual distribution of batted balls and so we can't draw any conclusions at all about what results Rendon or Jones should be getting on their balls in play from it alone.)
For the record, I think it likely that both Jones and Rendon are, indeed, suffering from unlucky batted-ball outcomes. I intend to investigate this, and the batted-ball luck of other players, in the coming weeks with the "xwOBABIP" stat outlined in my previous post on ball-in-play outcomes.
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