As many of you know, a player's batting average is directly correlated with a little stat called BABIP, or batting average on balls in play. The idea behind BABIP, is that a player's batting average, and therefore any statistic that takes into account batting average (such as OBP), is affected by a mixture of the opposing defense, a player's speed, and luck. Some players, such as Ichiro, are almost guaranteed to post a high BABIP each season due to excellent speed which allows them to beat out throws that most of the time result in outs. Defense plays a role in BABIP as a good defenses can take away any number of potential hits during a given season. Luck comes into play in the form of bloop singles that normally would be caught, or a diving catch that robs a player of a potential extra base hit. The average seasonal BABIP is in the .300 range and in the words of Fangraphs:
If a player has a very high or very low BABIP, it means that whatever the reason for the spike (whether it’s defense, luck, or slight skill), that player will regress back to their career BABIP rate. BABIP rates are flaky and prone to vary wildly from year to year, so we should always take any extreme BABIP rates with a grain of salt.
So, as you see BABIP is a statistic of high fluctuation, and each year many players experience outliers with their BABIPS, on both ends of the spectrum. The following 7 players that I will go into below each had an abnormally high or low BABIP in 2012 that differed from their career norms. While each of these players is likely to regress to the mean, there is no guarantee, as is best demonstrated by the emphasis of luck in BABIP.
Guys with unusually low BABIPS in 2012 who should bounce back
There were high expectations for Hosmer entering 2012, but he failed to live up to them as he hit just .232/.304/.359 compared to the .799 OPS he put up in his 2011 rookie campaign. Hosmer's season was definitely hurt by his .255 BABIP which finished as the 7th worst mark in baseball. In 2011, Hosmer had a .314 BABIP, and while it may be a bit too much to expect him to repeat that, most projection systems are predicting him to hit around the .275-.280 mark with a rougly .300 BABIP. Hosmer may not become the player many, including myself, projected him to be following 2011, but he shouldn't be nearly as bad as he was last season.
The former number 2 overall pick lacks pop in his bat (just a .102 ISO last year), so his future value resides mostly in his ability to hit for average. So far in his career, Ackley is a .243 hitter. He hit .273 in 2011, but struggled with a .226 average last season. Ackley had a rather high .339 BABIP in 2011, yet it plummeted to .265 in 2012. Ackley will need his BABIP to rebound significantly to become a source of value for the Mariners offense.
Ike Davis, 1B New York Mets
Davis hit just .227 last year, largely thanks to a criminally low .246 BABIP. Despite this, he still managed to slug 32 home runs with a .235 ISO. Davis is a power-first type of hitter, but he still managed to hit .271 in his one and a half seasons prior to 2012. A realistic projection for Davis would be for him to bounce back to a .250-.260 hitter, with a majority of his value embedded in his power.
As a former top prospect, Rasmus has stumbled significantly since his breakout 2010 season. Even a change of scenery from St. Louis to Toronto couldn't help him salvage his production. But the fact is, Rasmus probably was overrated to begin with. In 2010, a year in which he accrued 4.8 WAR, he had a .354 BABIP, well above the league average. Since then, his BABIP's have been .267 and .259 respectively. While his 2010 and 2011/2012 seasons represent the polar ends of the BABIP spectrum, 2 straight years of a sub-.270 BABIP is worrisome. Rasmus is an above-average defensive center fielder, so he will provide value even if his batting average fails to improve. ZiPS projects a .292 BABIP out of Rasmus in 2013, and while that is quite reasonable, it's hard to pinpoint an exact number due to his history of extreme fluctuations.
Guys with unusually high BABIPS in 2012 who should fall back to earth
Perhaps no player in baseball in 2012 benefitted greater from an extremely high BABIP than Torii Hunter. Hunter's .389 BABIP in 2012 was the 2nd best in baseball, behind only the guy listed below. For his career, Hunter has held a.307 BABIP, which is roughly in the league average range. His extreme luck resulted in a career high .313 batting average last season versus his career .277 rate. Hunter has been fairly consistent BABIP wise, as he has posted a BABIP between .285 and .320 in 10 of 13 seasons in which he played 90 or more games leading into 2012. While he is unlikely to hit .313 again, Hunter is also unlikely to hit .262 like he did in 2011. He should be expected to post a batting average in the .275-.285 range, which is certainly low compared to what the Tigers must be expecting since they gave him a 2 year, $26 million dollar deal earlier this winter.
Fowler's .390 BABIP in 2012 was the highest in baseball, and although he has consistently had high BABIP's (career .353 mark), Fowler had yet to top .354 until last season. Fowler's season last year is somewhat comparable to Luis Castillo's 2000 season with the Marlins. That year, Castillo had a .395 BABIP which helped enable him to hit .334. Like Fowler, Castillo was a guy who consistently had more of the balls he put into play fall for hits, mostly due to his plus-plus speed. In the year prior to 2000, Castillo had a .363 BABIP. This build up is also similar to Fowler as he had a .354 mark in 2011, before exploding last season. Unfortunately, Castillo's BABIP plummeted to .310 the following season, and he never again posted a BABIP higher than .346. Now comparing Fowler to Castillo is slightly unfair, since there is no guarantee that Fowler's BABIP in 2013 will fall as much as Castillo's did, but the point is, that even though Fowler is a guy with plenty of speed, his .390 batting average on balls in play is unsustainable. Fowler's BABIP should fall back into .330-.350 range next season, and while that still makes him a very valuable player, it is unlikely that he will hit .300 again.
Posey, the reigning NL MVP, won the batting title last year with a .336 mark thanks to a career high .368 BABIP. This is something that shouldn't be expected of him again for a couple of reasons. First, Posey had never had such a mark before in his career. Secondly, Posey is nothing special on the basepaths, and as a catcher, he will have more wear and tear on his knees that most players. These reasons alone make me assume that it will be difficult for Posey to repeat his high average next season. While Posey should be a roughly .300 hitter, the chances of him turning into Joe Mauer (a catcher with consistently high BABIP's) are slim.