Johnny Cueto and BABIP

A couple of months ago, when I first started writing about individual Reds, I wrote an article about Johnny Cueto. In it, I tried to temper enthusiasm about Cueto as his peripheral numbers did not point to the low ERA continuing. This morning, before heading to work, I made a similar comment, but this time focused on BABIP. Heads promptly exploded. Thus, I thought now might be a good time for a post that goes a little more in-depth. First, the problems with ERA. ERA does a perfectly adequate job describing what has happened. However, it doesn’t correlate very well from year to year. That is, a player’s ERA one year doesn’t do a great job predicting what it will be next year. Stats like FIP and xFIP actually do a much better job of predicting what a player’s ERA will be going forward than his current ERA does. That sounds odd, but it’s true. One of the reasons FIP and xFIP do a better job predicting future performance than ERA is that they try to pull lu...