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Demystifying BABIP

Oft-cited in sabermetric circles, BABIP is a frequently misunderstood stat and far less dependent on factors like "luck" than many observers would have you believe.

Kevin C. Cox

One of the most used and polarizing "sabermetric" statistics is batting average on balls in play, or BABIP. It’s a relatively easy stat to understand—simply measuring how many of a batter’s balls in play go for hits—but one that leads to countless conclusions and varying methods of analysis. Batters who have an abnormally high BABIP or those with an unusually low BABIP are frequently said to be "lucky" or "unlucky," and more importantly, overdue for their fair share of regression.

As a result, BABIP is often used in a predictive manner, as a way, in other words, to foretell a player’s impending fall back down to earth or to forecast their likelihood of snapping out of that nasty slump. On this level, BABIP can be a telling barometer for a player’s future chances of success.

But simply using BABIP as a way to label this player as especially "fortunate" and that one "unfortunate" glosses over the more nuanced factors of hitting at the major league level. Baseball, after all, is a complicated game.

Which brings me to Freddie Freeman, who, you might have heard, recently signed an eight-year, $135 million deal with the Atlanta Braves, the biggest contract in club history. You might also know that Freeman posted a .371 BABIP in 2013, the fifth-highest in baseball and a mark far above that of the major league average (.297).

Critics of Freeman’s contract (and other sabermetrically inclined observers) have pointed to his BABIP in 2013 as grounds for concern, and, furthermore, as proof he isn’t quite so valuable as the Braves might think he is. Many point to Freeman’s perceived lack of power for an elite first baseman (he matched a career-high with 23 home runs last season) and his high BABIP as indicators he could be in for some regression this season. This is a fair concern; if Freeman is closer to the player who hit .259 in 2012, then his lack of premium power makes him a player who is probably less valuable than the Braves believe him to be.

But Freeman was also among the major league elite in another category last season—line-drive rate. Since line drives fall in for hits far more often than other batted ball types, this is vital information to have when assessing Freeman’s present and future potential. In fact, since 2011, he has the ninth-highest line-drive rate among all major leaguers. Simply put, Freeman hits the ball hard, which means his balls put in play fall in for hits at a higher rate than can normally be expected.

The same can be said of Freeman’s teammate, Chris Johnson, who finished with the highest BABIP in baseball in 2013 at .394. That astounding mark has caused alarm bells to go off across the sabermetric landscape, with many rushing to conclude that Johnson is in for some serious regression in 2014. Yet Johnson, too, has an encouraging batted ball profile—he hit a lot of line drives last year (27.0% line drive rate) and also hit very few fly balls (27.5%), which rarely fall in for hits unless they become home runs.

Will Johnson’s .321 batting average from last year dip in the season ahead? Most likely. But barring some drastic changes in his approach, Johnson’s not going to fall off a cliff like some observers think. He has posted higher BABIPs than league average dating all the way back to his days in the minor leagues, a track record that is encouraging for his future prospects.

The same cannot be said, unfortunately, for fellow Brave Dan Uggla. The second baseman had a miserable season in 2013, hitting just .179/.309/.362 before getting benched for most of August and September (and each of Atlanta’s four playoff games).

Under certain circumstances, Uggla’s .225 BABIP would be a sign for optimism heading into 2014, but the 33-year-old’s batted ball profile was a disaster last year. His line-drive rate fell to a ghastly 13.2% (lowest in the majors), while he also hit fly balls 47.1% of the time. For a player who strikes out with such frequency, that’s far too many balls in play that are turning into outs. At the age of 33, with a strikeout rate that’s spiking and a league-worst line-drive rate, things don’t look too rosy for Dan Uggla.

Freeman, of course, is a different story, despite what you think his BABIP might initially indicate. Hitters with higher BABIPs than average aren’t necessarily in for regression, and neither are batters with unusually low BABIPs. How a hitter approaches his task at the plate and the types of batted balls that result from this are far more important factors.

In fact, given his track record of higher-than-average BABIPs during his career, the .295 BABIP Freeman posted in 2012 is more of an outlier than the .371 mark he finished with last year. Sure, Freeman may not be quite as stellar this season as he was in 2013, but simply pointing at his BABIP as evidence for a looming dip in production would be ill-advised and naive.

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Alex Skillin is a writer and editor at Beyond the Box Score and also contributes to SB Nation's MLB newsdesk. He writes, mostly about baseball and basketball, at a few other places across the Internet. You can follow him on Twitter at @AlexSkillin.