In the comment section of the delightful Animated FIP post from Monday, reader Marc wondered how you can quantify luck as it relates to baseball or pitching. Thankfully this isn’t impossible to separate skill from luck, at the very least we can identify when the two don’t quite line up.
Both pitchers and hitters feel the impact of the gods on their in play averages (or BABIP): the rate at which the balls they put into play are converted into outs. Statistically speaking, a pitcher should expect his in play average to hover right around .300. Some pitchers stubbornly manage to consistently post numbers below .300 and their ability to prevent runs1 benefits.
Hitters are subject to much wilder swings in their in play averages. Something as simple as their foot speed can help them steal base hits from situations in which slower guys record another mundane out. Fly balls and pop ups2 are great ways to make boatloads of outs, unless you happen to be the überslugger.
Typically, hitters maintain consistent BABIP (batting average on balls in play) from year to year. An unusual boost supports career years, uncharacteristically low seasons fuel endless slumps. Jack Moore of Fangraphs and Disciples of Uecker did a mountain of research showing fluctuations in batting average on balls in play has the single greatest impact on the four factors Moore identifies keys to production, in this case measured by weighted on base average.
The two Hank Aaron awards winners (pictured above with The Man Himself and the terrifying specter of death that is Bud Selig) the present incredible contrasts in the value of in play averages. Joey Votto — famous for his pop-up free season — finished 2010 with one of the highest BABIP in all of baseball, a robust .361. Jose Bautista managed a measly .233 BABIP during his monster 2010. It is important to note that home runs do not count in this calculation as they are not “in play”, making Bautista’s paltry figure easier to stomach.
Votto’s .361 mark stands out when compared to Bautista’s low average, but we must first consider the track records of both players. Votto brings a career BABIP of .353 to the table, so 2010 hardly represents a massive/unrepeatable leap in fortune. The magical swing changes and outlook adjustment made by Jose Bautista didn’t cure his typical BABIP woes, sporting a .270 career mark.
So we recognize that in play average greatly affects overall production and we know players tend to put up consistent batting averages on ball in play, but is there way to notice if something is askew? Of course! You think I wasted 400 words because I love the sound of my own voice?
Behold! The wonders of expected batting average on ball in play. The good people at the Hardball Times created (and then improved) a system to calculate an expected in play average. Based on historic batted ball information — with a speed calculation thrown in for spice — we are able to separate the unlucky from the ungood.
According the THT’s numbers, Jose Bautista missed his xBABIP by nearly 50 points! If his home runs start scraping the other, fair side of the wall; Jose is more likely to approach his expected numbers. Pitchers of the American League East shudder to think of the alternative: just as many home runs and walks with more singles and doubles thrown into the mix.
Joey Votto’s 2010 BABIP registered 30 points above his xBABIP of .334. As a guy who regularly surpasses his expected numbers, we can start to look at possible causes of error. The most glaring, in my eyes, is the manner in which these batted balls are categorized. As noted above, Joey Votto has a big fat zero next to his name under “infield fly balls.” While admirable, this may or may not be true.
The vagaries of batted ball categorization are murky at best, not to mention the source of much angst among the deeply nerdy. One stat stringer’s line drive is another’s fly out. Could Votto benefit from a liberal interpretation of what is or is not a fliner?
This is a great tool for fantasy players or desperate fans clinging to a shred of belief that somehow Carlos Pena or Aaron Hill can rediscover past form and not slowly suck the soul from the chests of an entire fanbase. Read the full post at the Hardball Times for more info.
1 – a.k.a. do their job.
2 – a.k.a. automatic outs.