This article is part of our The Saber's Edge series.
Last week, I examined how individual batted-ball profiles inflate pitcher ERAs. I'll now dive into how team defense and handedness splits get involved. The key to higher-than-expected ERAs is high BABIPs. As I showed last week, some of the differences can be attributed to the pitcher's overall profile. This week, I'll show how much of the difference can be attributed to team defense and handedness.
I've valued Robbie Ray quite a bit higher than just about everyone else in the industry; in fact, I recently ranked him as my No. 21 starting pitcher while none of my peers had him any higher than No. 40 overall.
Ray repels owners after posting a 4.90 ERA and 1.47 WHIP last season. A .352 BABIP caused those high numbers. While Ray's line drive profile leads to more hits, he doesn't get all the blame.
As a team, the Diamondbacks allowed a .320 BABIP leading to a team ERA (5.09) noticeably higher than its FIP (4.50). That's the fourth-highest BABIP any team has allowed since 2002. (Thanks, Yasmany Tomas.) The Cubs were on the other end of the spectrum; their .255 BABIP was the best mark over that time frame, and they posted a 3.15 ERA while their FIP stood at 3.77.
So how much of a team's BABIP tendency trickles down to the pitcher? Common sense says it should be near 1:1, but as I showed in my last article, the pitcher's profile matters. By taking all pitchers who threw