A few months ago after talking with Baseball Prospectus author Jonah Keri, I did a little research about what makes a pitcher successful. Nothing groundbreaking, but I like to do little research projects like that because they’re fun and I feel I learn more when I work through things on my own, rather than just reading it somewhere. What inspired the research was Jonah telling me that pitchers are generally more successful when they have at least two of the following three traits: a good strikeout rate, a good walk rate, or a good groundball to flyball ratio. And, intuitively, that just makes sense. A pitcher’s very basic job description is to keep as many men off base as possible. He can help himself out by…

A) Striking guys out. Because, unless Josh Paul is catching, you can’t reach base if you whiff. (Sorry, that was harsh!)

B) Limiting walks – don’t give guys free passes!

C) Inducing ground balls – while fly balls turn into outs a higher rate than ground balls, ground balls are good because they do less damage when they do go for hits. Like Orel Hershiser used to tell his pitchers, “When’s the last time you saw a ground ball go over the wall?”

Simple enough, right?

Well, the last time I saw Jonah was at the Baseball Prospectus 2006 / Baseball Between the Numbers book signing at the wonderful Third Place Books. I asked him what he thought about Raul Chaves, the Mariners’ new pitching coach, trying to teach some of the pitchers a two-seam fastball. The two-seamer doesn’t have quite the velocity that the standard four-seam fastball has, but it gets more movement – and is usually better at getting ground-ball outs.

Jonah suggested that I e-mail Will Carroll with that question, so I did. I told Will what Jonah told me about successful pitchers and asked him if teaching pitchers the two-seamer could help to improve their GB/FB ratio. Will was nice enough to e-mail me back and here are some things that he said…

“I disagree vehemently with Jonah on that, but that's not your question. Can teaching a pitcher to sink it or keep the ball down help? Sure, if he executes. I like that Chaves is at least trying something. It depends on the teacher and the student.”

I found it very interesting that Will disagreed with Jonah on the issue and asked him what he thought made a pitcher successful, to which he responded, “Health, location, and deception. Give me five Greg Maddux’s and I'll rule the world.”

Here’s the catch though: Jonah's keys to pitching success are results, whereas the keys Will listed are the traits that lead to the results. Health allows pitchers to pitch, location leads to low walk rates and sometimes groundballs, and deception leads to strikeouts and groundballs. Maddux has sure been healthy. His lowest inning total since 1988 is 199. Of course that’s part of the reason for his Hall of Fame career, and it’s obviously important to try and keep any player healthy as much as possible. So, while Maddux does have pinpoint location and great deception, he’s also always had decent strikeout numbers combined with an above-average groundball rate and good-to-great walk totals.

Will may disagree with Jonah about what makes a successful pitcher, but I hope they don’t waste too much time and energy arguing over it because I think they’re both correct!