Advanced baseball stats, or sabermetrics, are an integral tool for fantasy baseball managers. You don't need multiple advanced degrees in applied mathematics to use advanced baseball stats effectively, and this article will be strict a "no math zone." What we'll focus on instead are statistics and ideas that will help you predict key fantasy stats and win your fantasy baseball leagues.
BABIP is the most accessible of the advanced stats. Despite arguments about how to pronounce it, everyone agrees that the acronym stands for "batting average on balls in play." BABIP measures a player's rate of turning contact into actual hits, and it's important because it's an approximation of luck, with a particularly high or low number indicating regression in the near future. Thus, BABIP can be used to spot buy and sell candidates in your leagues -- guys who deserve extra attention from you in your quest for a fantasy championship.
Use BABIP to Predict Future Performance and Win Your Fantasy Baseball League
BABIP can give fantasy managers a better understanding of how MLB players will perform moving forward. Think of it as analytical ammo to gain an advantage over your competition.
The general rule of thumb is simple: league average BABIP hovers around .300. In general, if a player's BABIP is above .300, they might've been lucky and darker days could be ahead. For example, weak contact managed to squeak through the infielders for some "cheap" base hits. Conversely, if your BABIP is below .300, you might've been particularly unlucky and better performance should be coming. For example, a line drive was hit right on the nose, but right at the defender.
Over the long haul, those hard-hit line drives will eventually turn into hits, while those softly hit grounders will more often than not become outs.
Exceptions to the BABIP Rule
While .300 is the league-average BABIP, each player's skills contribute to a personal BABIP that tends to run better or worse than average. Dee Gordon, last year's NL batting champion, is a prime example. In 2015, Gordon was drafted for elite SB totals, but no one complained about his .333 batting average at season's end. The BA was a shock, as Gordon had hit just .289 the prior year and has never looked like a "batting champ." The answer lies in Gordon's ridiculous .383 BABIP. We'd expect that to regress to .300, right? Not necessarily. Because Gordon is an elite speedster, it makes perfect sense that his wheels could help him beat out more grounders for base hits, and thus to consistently turn in a great BABIP.
Gordon's career BABIP is .346, clearly indicating a sustainable ability to beat the league average of .300. So how do we know whether his .383 was lucky? To find out, we'll have to examine his BABIP by batted ball type.
We've established that Gordon's speed helps him beat out grounders. He managed a .316 BABIP on grounders in 2015 (league average is .250), consistent with the mark he posted in 2014 on his way to a .289 BA. This tells us that a) Gordon can consistently outperform the league average BABIP on ground balls, and b) ground balls were not the reason Gordon's BABIP spiked to .383 last year.
Gordon's average spike actually came from line-drive performance. In 2014, Gordon posted just a .561 BABIP on liners, over a hundred points shy of the league average of ~.700. In 2015, this number jumped to .748, well better than league average. That said, nothing in Gordon's skill set signals he can maintain 2015's rates. His career line drive BABIP comes in below average at .668, indicating he is due for BABIP regression and batting average regression in 2016. A BABIP of .350 is still a real possibility with his speed though, so his BA should fall between 2014's .289 and last season's .333. Despite Gordon's upcoming regression, RotoBaller's expert rankers love him in 2016, as he sits at No. 23 overall in our consensus Fantasy Baseball Rankings.
The bottom line, though, is that if Gordon starts the year with a .350 BA, owners should capitalize on his good fortune by selling high. If Gordon is batting .250 in April, sit tight and wait for that BABIP rebound to kick in, or reach out to his owner to see if you can buy at a discount.
Knowing When Future Performance Won't Be Impacted
Baltimore's new $160 million dollar man, Chris Davis, is well known for being an all-or-nothing slugger who pulls the ball at every opportunity. This makes him susceptible to defensive shifts, since the infield has a pretty good idea of where the ball will go, and they can set up accordingly. This has hurt Davis's BABIP on grounders, as his .195 career figure certainly attests. In his case, then, it's clear that projecting regression toward the league average of .250 would be a big mistake. Davis's overall BABIP was nevertheless above average last year, however, which tells us that while he couldn't get much out of ground balls, he sure smashed the hell out of his fly balls and line drives.
To conclude, fantasy managers can use BABIP to measure a player's batting average luck by comparing it not to the league average of .300, but rather to the player's own established career numbers. Foot speed, as well as other factors like batted ball authority and defensive positioning, inform a player's individual BABIP. Players with certain skills can manage to maintain a consistently high BABIP, and thus they represent good buying opportunities when they start out a season in a cold stretch. Players without those skills, however, may still manage to beat the league average once in awhile by sheer luck, and these guys represent the prime "sell" candidates to bring back some value before their performances normalize.
If you want to see how BABIP luck can be applied to pitcher evaluation, check out this other article in our Fantasy Baseball Strategy Series.