Analyzing xBABIP: Hold Onto Your BABIPs (Part 3)

xBABIP is a way you can evaluate your players to find sell high opportunities. in part 3, we are covering players whose BABIP outpaces their xBABIP.

Statcast has given us a lot of data to play with and those smarter than I am are putting it to good use. Andrew Perpetua released his new batting average on balls in play results on Fangraphs, titled xBABIP. And as always, I want to dive into these to determine if we can syphon any underlying value in analyzing a player’s potential fantasy value. If you read part 1 or part 2, you can skip to the section where I talk about the BABIP and xBABIP differences. And in part 3, we are covering players whose BABIP outpaces their xBABIP.

EXPLAINING XBABIP

BABIP alone is batting average on balls in play and the calculation is pretty simple; out of all balls put into the field of player (excluding strikeouts, excluding home runs essentially), what is that player’s batting average? League average BABIP is right around .300. Here is the formula below.

BABIP = (H – HR)/(AB – K – HR + SF)

So Perpetua is taking that same concept but using strictly Statcast data to create a BABIP based on a player’s batted ball abilities. He does a pretty good job at explaining his process and the kinks that haven’t quite been worked out in the article linked in the opener. But here are a few points I’ll highlight.

1. xBABIP is looking to pull out the luck aspect of BABIP from itself. Ever get into an argument with someone over whether or not X Player’s BABIP is luck or skill? Well this attempts to separate those so we can determine if an above average BABIP can be credited to a player for just being a damn good hitter.
2. Physics complicates things and Perpetua admits as much. The longer the ball hangs in the air means the longer time a player has the chance to make a play. He hasn’t quite worked out how to measure this with 100% accuracy.
3. His version of xBABIP is a pure batting stat and “only measures the player’s ability to bat the ball…conducive to reaching base safely.” This means two things:
   • He isn’t incorporating player speed, as a fast player will typically result in a higher BABIP even if his xBABIP is lacking.
   • This doesn’t take into account shift data as of yet. So player’s with lower BABIPs due to successful shifts against them might result in higher xBABIPs.

THE APPLICATION OF XBABIP IN EVALUATING PLAYERS

Now those two subpoints above are being worked on but I also wonder if he even should. A big contention in pitcher evaulation and the reason we have xFIP and FIP is a result of the home run ball and is it able to be controlled by the pitcher. Some evaluators pick a side on which is the better stat but the truth is you should use both; for some pitchers, it’s more appropriate to use FIP — like Jordan Zimmerman or Gio Gonzalez, who have produced a below average FIP for pretty much their entire careers. Other pitchers and other circumstances call for us to use xFIP to evaluate pitchers.

I see that if we can hone and tone xBABIP, we can use it similarly to how we use discretion when using xFIP and FIP. Where BABIP might be more appropriate for your Dee Gordon‘s and xBABIP might be more appropriate for your David Ortiz‘s. Or not. We really don’t know yet.

But what I love about this new metric being able to calculate BABIP using only batted ball data (Statcast specifically) is that I finally have data to point to when we make assumptions about BABIP. For example, a lot of people have said Nick Castellanos is about to crash back to earth. To which I responded in a thread, “Regression is coming but people who point to his BABIP being unsustainably high…that’s what happens when you have a 31.1% Line Drive rate. You are going to have a way above average BABIP at that point, especially when you are only making Soft Contact 10% of the time.”

Well in that instance, I was simply using the Fangraph provided Batted Ball data to make an assumption that a guy who hits line drives at that rate will have a great BABIP. But now with xBABIP, I actually have a BABIP to point to to say, “This is where his BABIP should be because he is hitting those line drives at that particular pace with the quality of contact he has shown.”

So in defense of Castellanos — who I selected as my No. 1 breakout third baseman earlier this year — I’m interested to see what his xBABIP is. And at the point of writing this sentence, I have no idea what his is yet; I said in that same comment, “He’ll fall somewhere between what he is doing now and what he did last season…” and let’s see if I’m right. But first, in looking at his spreadsheet, here were some things I’ve found.

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PLAYERS WITH HIGHER BABIP THAN XBABIP

The chart below highlights players with at least 100 PAs* that I felt were interesting enough to include. If you want to search particular names, Perpetua provides a download to the list in his article. Since my last article, some of the players xBABIP and BABIP differences have started to normalize but we still have some interesting names.
Many of these are players that I pegged as sleepers candidates this year — still not sure if this is a good or bad thing! But players like Odubel Herrera, Brett Lawrie, Marcus Semien, Stephen Piscotty, and Nick Castellanos are all players that I had listed at their respective positions. I picked them as sleepers for a reason so to see them on this list isn’t surprising but I may touch on them in the next three categories.

1. The Speedsters

So as I predicted, man there are a ton of speedsters that made this list. I even included Dee Gordon to prove that point. Those with BABIPs that far exceed their xBABIPs will generally have some speed at play here.

Jonathan Villar has been the saving grace for many teams this season. Currently ranked a top 5 player  on the ESPN Player Rater, he has proven his worth this season. He is able to achieve a BABIP close to .400 on his speed but not speed alone. The guy is a very good hitter, with just Batted Ball data alone calculating a .321 xBABIP. Considering the average is around .295-.300, we are seeing a player that we can trust moving forward. Monitor his K and BB rates moving forward.

Ditto with Byron Buxton. Say what you will about his strikeout rates but his return from the minor leagues has come with a different looking player. His most recent performance in the minor leagues was something we had never seen from Buxton to date. With 80 grade speed, this guy has the chance to produce amazing BABIPs to go along with his .348 xBABIP. Prep for stabilization and his K-rate may suppress his batting average, but I like what I see from Buxton so far.

We could really go over all the players who qualify as speedsters but the main point here is that speed affects BABIP, regardless of how well you are able to connect with the ball. And in that, you are able to affect you average and the bottom line. Some guys are striking the ball very well: Xander Bogaerts, Stephen Piscotty, Jonathan Lucroy, and Starling Marte. And they have the speed to back it up.

Some of these players are striking the ball below average or average. Some names that stick out to me who still have that speed factor are Jacoby Ellsbury, Carlos Gomez (shocker), Marcus Semien, Josh Harrison, Brett Gardner, and Carlos Gonzalez. Some of these guys I won’t touch with a 10 foot pole (Gardner and Ellsbury) but I do love what Harrison is doing and I actually think Gomez is someone to closely monitor.

2. Lucky Players

First off, let’s get right at the first guy on the list and that’s Mike Napoli. He is virtually doing the same thing as he did last year; his 2015 xBABIP was .253 and this year’s is .252. Yet, he has someone gained 40 points in BABIP. Now, his average has only risen ten points but that’s largely due to his K-rate sky-rocketing to 36.6%! I’m not saying to sell on him because he has raised his Hard% to 43.9% which is amazing and will allow him to continue to hit home runs. But he will have cold streaks.

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Hello Jackie Bradley Jr! I recently gave you some dap about how you could be this season’s Shin Soo-Choo if the Red Sox offense keeps rolling along. But to be fair, you are getting a bit lucky. For a guy who should be neutralized fairly easily with the shift, Bradley has been outperforming himself. That BABIP will fall soon and so will the average.

Adrian Gonzalez is maintaining an average right in line with what he has done the past two seasons…for now. He isn’t hitting home runs at the rate he did the past few seasons and that is paired with a .291 BABIP. For a player like Gonzalez, he needs those home runs to buoy his average. So last season, his .294 BABIP was supported by his .295 xBABIP. And his FB% has fallen to just 23%, which means it looks as though the home runs won’t be coming back. His average is about to drop and we are seeing a guy who could end the season with a .260 average, with 15 home runs, and under 70 runs and RBIs. Yikes. Sell while you can.

3. Players I Want to Touch on

This is a different category because there are some players who I don’t want to chalk up as lucky. I also don’t want to call them fast base-runners because stolen bases may not reflect that nor do I have any forty-yard dash times available.

I have been an Aledmys Diaz hater since he came up. What a season he is having but it’s been almost two months worth of data for me to finally say……I still don’t know what the hell to think.We are about that time of the year where it’s very hard for people to use the small sample size argument against what Diaz is doing. But he truly is an average hitter with average speed. He is able to keep his average up due to his 12.3% K-rate, but I think he is a player you could get some really good value out of if you sell. Or keep riding him.

Ian Desmond is absolutely unreal and by my measure, is striking the ball better than he ever has. We don’t have xBABIP going back to 2012 — the last time he hit for a .292 average — but his soft contact rates are down, hard contacts rates are up and he is hitting line drives again. Most importantly, his K% is at 21.1% which is back to his 2012 level. And you have to like his home ballpark.

While Miguel Sano hits this list with a .271 xBABIP, it is to be expected (Note: Chris Davis was on this list as well). He hits a monstrous amount of flyballs, he hits the ball very, very hard, and he will routinely have a low batting average because of those flyballs. But the home runs will offset it. He was on pace for a 35 home run campaign and that’ll be just fine for a guy who will probably sports a .240-.250 average. Yes, he is basically Chris Davis.

Personally, I would sell on Jung Ho Kang. He won’t maintain his 50.7% Hard Hit Rate and his near 50% Fly Ball rate is the reason why his average is outpacing his BABIP. To the untrained eye, it looks like Kang picked up right where he left off but his .217 xBABIP says he has a generous home run to fly ball rate being able to keep that average as high as it is. No, he won’t absolutely tank but I think you could get great value for him.

So Justin Upton is a guy that many people want to know what is going on with. Truthfully, the man has actually raised his xBABIP from .269 last season to .314 this season. He is hitting more line drives and is posting the best distribution rates of his career. His Soft% is up to 22.9% but that should stabilize. The dip in average is because he is now striking out 35% of the time. Unless that falls, his average will continue to hover around .240.

CONCLUSION

So you have your speed demons and you have your guys that are very fortunate and are probably sacrificing buckets of fried chicken with Pedro Cerrano before each game. And then there is Justin Upton. Regardless, the analyzation of xBABIP is so you don’t just throw out BABIP blindly without any basis. This happens routinely to discredit a player’s success or give reasoning for why a player should bounce back.

Next: Vincent Velasquez Injury Scare

A proper analysis of the xBABIP and BABIP relationship with all the dirty details in between will get you where you want to go. But since everyone doesn’t have time for that, that’s where I come in. I hope you enjoyed this series. The next article you see will be the highest rated xBABIPs in the league…for pitchers. The guys who are the absolute best at getting weak contact.