We were discussing Soto’s shitty, shitty 2009 luck in the last thread. In a previous post, MB pointed out that Soto’s batting average on balls in play (BABIP) and its expected value (xBABIP), based on his hit-type distributions were a whopping 63 points apart in 2009. What could we have seen if he weren’t so epically unlucky?
First, a few comments on where I’m getting all this info from. The state-of-the-art in xBABIP is this calculator from THT, which is what MB used to generate the xBABIP numbers in that post. But I’m going to back away from that because it uses more variables than I’d like to include right now (hence the ‘crude’ estimation disclaimer in my title). Obviously a players speed and plate discipline is going to have an effect, but I’m just going to boil it down to LD%, FB%, and GB%. One could also try to normalize his HR/FB luck, but he wasn’t especially unlucky there this season. I’d actually expect it to be lower given that he was injured.
Instead, I’m going to use these numbers from fangraphs. These rates are for pitchers, but like I said, crude estimate.
LD to hits: 73%
FB to hits: 15%
GB to hits: 24%
Here are Soto’s batted ball percentages (and numbers of each type)
LD: 47 (18.1 %)
GB: 105 (40.5%)
FB: 107 (41.3%)
Using these (and subtracting his 11 HR off of his FBs), I get a crude xBABIP of .298, still much higher than his actual BABIP of .251. So what would we get if we add in those extra hits? If we make the crude assumption that they are all singles, it would add an extra 13 hits to his numbers for the season, which would make his slash line .256/.360/.419 and a wOBA of .340

1. berselius (view all comments) — Nov 15, 2009 @ 01:53 PM
I might update this some more later if I have time. I was trying to generate some numbers on the correct distribution of how singles, doublesm triples, and HR should go with each batted ball type but was getting strange numbers (like a HR/FB rate of 40%). Got too frustrated. If someone can point me to where those numbers are (if someone else has them) that would be great