Luck plays a big role in baseball, as it does in all things, and no where is that discussed more than in looking at a batter (or a pitcher's) BABIP. BABIP stands for Batting Average on Balls in Play and the reason we look so closely at it is because once the batter puts the ball in play, the outcome is out of his hands. As a result, we expect batters to all show a roughly average BABIP (about .300) and anytime we see anything significantly larger or smaller, we assume the batter has had good or bad luck.
This is exactly the kind of thing that leads Jason to give BABIP a prominent place in a discussion of Yan Gomes' potential for 2014. When we see a number like .342 in the BABIP column, the assumption is that this player is due to regress in a big way. But there is more to it than that: Look at the career numbers of someone like Michael Bourn. If BABIP were all luck, his career figure of .342 (there's that number again!) would be highly unlikely. It isn't just luck though.
Certain players (particularly those who hit a lot of line drives and those with a lot of speed) tend to have higher than average BABIPs while others (particularly those who hit a lot of fly balls) tend to have lower than average ones. This is where the idea for xBABIP or Expected BABIP came from.
Line drives fall in for hits almost 75% of the time, far more often than ground balls (~20% of the time, not counting infield hits) and fly balls (~13% of the time). Infield flies are almost never hits. Infield and bunt hits, on the other hand, are basically bonuses - hits that only certain guys can get because they bring something else to the table: speed. xBABIP adjust's players hit totals based on their batted ball profile, giving them credit for hits on ~20% of their ground balls, ~13% of their fly balls, etc.
There are a number of places out there where you can calculate xBABIP (I'd recommend this one if you want to play around) but, thanks to inspiration from our brethren at Talking Chop, I am going to do some of the work for you. The chart below includes the 11 returning regulars and the one new addition expected to join them and compares their 2013 BABIP to their xBABIP. In the "Diff" column, positive numbers mean good luck (the player got more hits than expected) and negative numbers mean bad luck (fewer hits than expected.
A few relevant notes:
* Not surprisingly, the players who probably put up the two most unexpected good seasons last year sit atop our list. Gomes is the more concerning case, as his role is expected to expand in 2014 and his BABIP could be in for quite a tumble based on this data. But he also had regularly high BABIPs in the minors, so I wouldn't count him out yet. Raburn doesn't have nearly as far to fall, but he did get away with some good luck in 2013.
* Jason Kipnis is a perfect example of why we have xBABIP. At .345, his BABIP looks insanely high - and it is a bit high. But the difference between his actual and expected BABIPs comes down to about 2-3 hits. So, basically, every other month, Kipnis got a hit that he maybe shouldn't have. That doesn't mean he will post another .340 BABIP, but it does mean his 2013 performance was not particularly luck-aided.
* At the other end of the spectrum, you have David Murphy, and I can almost guarantee the Indians looked at data like this before deciding to offer him a contract. That .227 BABIP is atrocious and in reality he hit like a guy who should have been much, much better. Murphy would have needed 25 more hits for his BABIP to match his xBABIP. Even if we assume they were all singles, that changes his average, OBP and SLG from .220/.282/.374 to .278/.335/.431. And realistically, some of those lost hits would have been for extra bases, pushing up the SLG even further.
*A couple weeks ago, Ash asked if this was Chisenhall's last chance and, at least based on this, he certainly deserves another look. He was almost as unlucky as Murphy, and giving his line the same treatment, we go from .225/.270/.398 to .273/.315/.446.
As you can see, the Indians had a handful of other players hit into some bad luck this year. This group, as a whole, had a BABIP of .293, which doesn't look too bad at first. But their expected BABIP was .312, which works out to a pretty significant difference.
Just because the Indians had bad luck in 2013 doesn't mean we get to assume good luck in 2014, but even if they just revert to no luck at all, it should mean a nice step forward for the offense.