Over the past 4 days, Six Man Rotation’s CRA metric for pitchers (or, as some of you may have seen it before, XRA) has gotten a bunch of good feedback. If you haven’t seen it, here’s the what, how, and why of CRA. Some really like it, and some have brought forward their own skepticisms, which is absolutely welcomed.
When I first posted “XRA” on Twitter, I was surprised to find that the name XRA was already taken! Michael Francis posted this article on the Fangraphs community research page nearly 2 years ago. Francis’ XRA existed within the same thought as SMR’s CRA, but is ultimately a different formula.
So, out of respect for Francis, the name has been changed to CRA, or Classified Run Average. I think this name makes sense for a few reasons:
1. “Expected” Run Average, to a degree, is misleading. Based on a pitcher’s past performance, we can calculate CRA based on his K%, BB%, and quality of batted balls allowed, but it shouldn’t necessarily be “expected” for the future, as xStats have shown limited predictability.
2. The “classification” of batted balls is what allows xStats to work, as all similarly hit batted balls are grouped together to give a rough estimate for xBA and xSLG, hence Classified Run Average.
The name may not be perfect, but it’s about what the number can hopefully tell you that’s more important. I flipped through about 30 different names in my head, but CRA was the only acronym that either wasn’t taken or wasn’t a mouth full.
“Shut up, dude, we want the leaderboards.”
At all times, you can also find these under the LEADERBOARDS tab at the top. As of now, the boards are pretty elementary, with limited sorting and so on. After populating the 2017 and 2016 CRA leaders, hopefully we can make front end improvements to make the leaderboards more dynamic. Enjoy!