Pitcher BABIP and ERA Corelation

[Goober]

After reading an article about Gerrit Cole's low strike out numbers, and why it may or may not be a good thing; I became curious about overall trends in pitcher BABIP across MLB. I putzed around with some figures on Fangraphs and figured I might as well post some of the data.

This is exactly the same philosophy that Jordan Zimmermann has been employing (quite successfully) as well as Stephen Strasburg (with mixed results). It stresses the avoidance of falling into deep counts and walking or striking out hitters.

One important characteristic of both Zimmermann this year and Cain in his dominant stretch (2009–2012) are their lower-than-average BABIPs. Zimmermann is at .260 this year, and Cain has been at .259 since ’09. If you’re not striking guys out, after all, you have to make up those outs on defense—ideally with weak contact. Cole hasn’t gotten the hang of that yet; his BABIP is right around the league average of .293—and that's only after the .056 posting from last night's game against Washington.
http://www.beyondtheboxscore.com/20...-cole-pirates-strikeouts-must-they-never-meet

I decided to take a look back at the last several years, and see what kind of correlation BABIP has with pitcher ERA. Was Matt Cain's good fortune a skill that is shown repeatable across the MLB pool of pitching talent? Or was he simply an outlier.

Nothing earth shattering here. While there is some correlation between pitcher ERA and BABIP, it's not very significant. One thing I found interesting is the amount of closers that significantly outperform their expected ERA relative to their BABIP. No wonder Ruben Amaro has so much trouble developing a closer! Low BABIP is a skill that is difficult to teach, especially when you employ the likes of Ryan Howard, Delmon Young, Dom Brown, Michael Young, and Jimmy Rollins!

Here is the leaderboard that I used for the data in case you'd like to see where your favorite player sits on the graph:
http://www.fangraphs.com/leaders.as...am=0&rost=0&age=0&filter=&players=0&sort=12,a

 

[ThomasTomasz]

Sidney Ponsum.........:lol:

God was that dude a bum.

 

[Villain]

I didn't realize Valverde had such a low BABIP.

What is the correlation between BABIP and FIP?

 

[Goober]

I didn't realize Valverde had such a low BABIP.

What is the correlation between BABIP and FIP?

As one would expect, basically zero.

 

[dell71]

My first thought on why there isn't a significant correlation is that it's because of the home run. Theoretically, and no I haven't tested this, guys with high ERA/low BABIP give up a lot of homers. After all, ERA includes and is directly affected by home runs while BABIP leaves them out. Again theoretically, pitchers with low ERA/high BABIP don't give up as many dingers because, on average, they're more likely to be ground ball pitchers. We do know that ground ball pitchers tend to have higher BABIPs but lower ERAs than flyball pitchers who give up homers.

 

[Goober]

My first thought on why there isn't a significant correlation is that it's because of the home run. Theoretically, and no I haven't tested this, guys with high ERA/low BABIP give up a lot of homers. After all, ERA includes and is directly affected by home runs while BABIP leaves them out. Again theoretically, pitchers with low ERA/high BABIP don't give up as many dingers because, on average, they're more likely to be ground ball pitchers. We do know that ground ball pitchers tend to have higher BABIPs but lower ERAs than flyball pitchers who give up homers.

More graphs, just for fun. Really no correlation at all between any of them.