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 luck out of the equation. BABIP, the stat I mentioned this morning, is heavily influenced by luck. Some comments claimed my assumption that Cueto’s current .227 BABIP is unsustainable is flawed because it doesn’t look at context.

To an extent, they are correct. BABIP will, generally, hover around .300, but there is variance amongst pitchers that can be seen over the course of long careers. However, I would assert that no pitcher can reasonably be considered to have the talents necessary to maintain a BABIP as low as Cueto’s. For evidence, I’ll direct you to this article over at The Hardball Times. In it, they look at the 25 pitchers with lowest and highest BABIP for one season. What they find is a huge regression. That is, pitchers with really low BABIP see the number go way up the following season and vice versa.

What you get, if you weed through the data is that you should almost never give a pitcher any credit for a BABIP below .280 because that is almost certainly luck.

To look at an extreme case, take Greg Maddux. Maddux, I think we would all agree, is in the conversation for best pitcher ever. His career BABIP is .281. During a four year stretch from 1992-95, when he was at the height of his powers, he was able to keep his BABIP below .260, but here we are talking about four of the best pitching years ever.

So what about Cueto? He’s definitely become a different pitcher this year. His groundball percentage is way above average and his line drive percentage is third in the league. These are both numbers that point to a low BABIP, and if he maintains these levels, we can expect him to keep his BABIP well below average, just not at .227.

Cueto has already shown an ability to outperform his FIP, and I’d expect him to keep that up. As long as the new Cueto is real, we should expect him to maintain an ERA just a bit above 3.00 going forward. That, by the way, is still excellent. But, whether we like it or not, Cueto’s current 1.94 ERA is a mirage, and we can’t expect it to last.

Last, and unrelated, I’d like to ask which players you’d all like to see me write about going forward. To his point, I’ve covered most all of the major players: Bruce, Votto, Phillips, Stubbs, Hanigan, Wood, Leake, Cueto, Bailey, and Arroyo. So point me in a direction and I’ll do my best to give you what you ask for.