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Rays Roundtable: Considering BABIP and IFFB%

Investigating the Rays offense's low BABIP, high IFFB%, and the park factors of Tropicana Field.


This morning's discussion of Chris Gimenez in the Rays Tank brought up an interesting point about Gimmer's Batting Average on Balls in Play (BABIP) against left handed pitching. Giminez had a limited sample size for discussion purposes, but the topic has merit, as the Rays offense was near league worst in this category last season.

BABIP begins as a pitching statistic, measuring how many ball in play against a certain pitcher go for hits. This statistic is largely influenced by the defense behind the pitcher, the luck of the ball as it was struck, and changes in talent level across a season. BABIP is also transitive. If you are counting the number of balls put in play against a pitcher, you can count the number of balls put in play per batter. This is where the Rays have struggled.

The conversation on Gimenez reminded me of an e-mail chain the DRaysBay writing staff had the day David Price won the Cy Young Award, which focused on comparing the Rays offensive performance in 2012 against the rest of the league, which I documented in a spreadsheet at the beginning of the offseason...


This google doc compiles a few key statistical categories for MLB offenses, as well as the pitch selection used against those teams. In the spreadsheet I've added some color coding, where Red/Yellow denotes a low score and light/dark Green denotes a high score, but the colors are not meant to indicate "good" or "bad".

Using the sheet, we can see that the Rays had horrible numbers for BABIP, flyballs (FB%), and especially in-field flyballs (IFFB%), three statistics that appear to be interrelated. Jeff Zimmerman made this observation earlier in the off-season for an article on Fangraphs, where he noted that tendencies toward in-field fly balls can be correlated to BABIP.

My first suspicion was that the Rays experienced an increased IFFB% due to an increased use of cutters, hence the inclusion of pitch selection. The Rays were on the high end of cutters faced, but there did not appear to be a league wide correlation between certain pitches and IFFB%.

So this leads me to two questions:

1. Do the Rays have a BABIP problem?
2. Do the Rays have a FB% or IFFB% problem?


It's a lot to sort through, but by looking at the team level, I bet you're capturing park effects. The thing I'd like to see is if we could connect that spreadsheet to groups based off of hitting philosophy, our hitting coaches with similar quotes. Of course, flyballs in general have the lowest BABIP rates, so it is no surprise there.


Park effects is a legitimate concern. I haven't done any research on hitting philosophies, but there seems to be a correlation between the bottom four teams in low BABIP, high IFFB% and high FB% -- but with the high BABIP teams the opposite was not true. If this was a result of park factors, shouldn't it work both ways?

BABIP seems to be a skill for hitters, look at the Cardinals. Is the takeaway that the Rays need to sign players with smaller FB% and IFFB%?


That would help their BABIP, but probably hurt the homerun outage. You should be most worried about assembling the best hitters, whether they hit flyballs, groundballs, or line drives.

I'm not very familiar with the Trop's park factors, but it looks like it is better to be flyball heavy than groundball heavy. Infield fly balls should be avoided, and is a sign of a weak hitter.


According to Weaver, you should assemble the team based on the park. If you have a team that plays in KC, for instance, you don't have a bunch of fly ball home run hitters or the balls will turn into outs on the warning track... Weaver suggested that you'd want a bunch of line drive guys that hit the alley, high contact guys with speed. He said his 3-run homer hitting Orioles teams would have lost 10 games more a year if playing in KC as opposed to Baltimore.

Interesting guy that Weaver was.


Generally, a GB is worth as much as a FB, but park effects matter for how those outcomes get translated into runs. I don't know the park effects for the Trop, and how it relates to that.

Overall, the Trop is a pitchers park, which means the entire run environment is lower there. That means that a single run is worth more. While a GB and a FB have the same average run expectancy, they surely get to it by different run expectancy curves.

I suspect that the FB's curve is shifted toward less probability of single runs, but higher probability of big scores (once again, I don't know this for a fact, but I think I'm right). That means that in the low run scoring environment, the single run is worth relatively more, and the GB hitter is worth relatively more.

On the other hand, the GB hitter is worth relatively less on a high walk team that often has a man on first base waiting to be doubled up. Is the run environment change from the Trop enough to actually matter? I have no idea, and I sort of doubt it, but there it is.


I think the Rays position in the bottom four in regards to BABIP has more to do with the skill set of their hitters than anything else. Rays hitters love to pull the ball. Not only do they love to pull it, but they are good at it compared with the rest of the league. The main issue issue is that Rays' hitters were also awful at hitting pitches the other way, making them vulnerable to shifts.

The Rays low BABIP is most likely the result of Pena, Scott, and Joyce being pull-heavy hitters, lowering their BABIP, in addition to a poor assortment of hitters and bad luck.

As far as responding by pursuing free agents with a low FB%, I have to disagree. The whole idea should be to collect a group of hitters that gives the Rays the best chance of winning. If the Rays have a low BABIP but are able to produce runs, then I am all right with that.

Another aspect to look at is the Trop's park factors. According to Fargraphs' park factors, the Trop is more favorable to flyballs than groundballs. So if anything, the Rays should probably defer to a flyball hitter.


I generally agree with Michael -- that the Rays' low BABIP is likely a result of the pull-heavy nature of their hitters -- but I think there might be something else in play here too: their division. If you look across the AL East over the past few years, the only team to consistently have an above average BABIP is the Red Sox, and Fenway Park is likely a very BABIP-friendly park. Meanwhile, the Rays, Orioles, and Blue Jays have all rated in the bottom third of the majors in BABIP, while the Yankees have averaged around the middle of the park.

Could there be something to this? I feel like one could make the argument that AL East teams have been among the early adopters of the league-wide shift towards valuing defense, and they have all started to liberally use defensive shifts. Could part of the Rays' problem be their opponents? In addition, the Yankees and Red Sox have generally had quite strong pitching staffs (outside last year), and good pitchers can reduce BABIP slightly.

The conversation ended here, when David Price won the Cy Young award and the thread completely changed direction, but it raised a number of good points.

Do the Rays have a BABIP problem? If so, is the blame on the players or the park? Is BABIP even worth discussing? Let us know your thoughts.