Up until last week, I had talked primarily about luck indicators. That is, statistics which are prone to unexplained fluctuation. When we examine these types of statistics, we try to see who is getting lucky or unlucky. Last week, though, I talked about strikeouts and walks. Strikeouts and walks are a different type of statistic. They are performance statistics, or skills. They are generally more predictable and less influenced by luck. Put simply, they are more indicative of skill. This week, I’ll examine another skill statistic: ground ball rate.

Ground ball can be calculated in two ways. The first, simplest way, is the by using the following formula:


The way I calculate it, though is like this:


By calculating it like this, the result isn’t much different, but it is slightly more accurate. This way eliminates things like bunts that pitchers have, essentially, zero control over. For this article, I’ll be using the second formula to represent GB%.

While strikeouts and walks are the most important skills for a pitcher to have, a pitcher who gets a lot of ground balls can be successful as well. Ground balls are good, primarily, because they are not fly balls. As we discussed last week, pitchers don’t have a whole lot of control over their line drive rates, so that really leaves just two types of batted balls they can control: ground balls and fly balls.

The biggest reason ground balls are better than fly balls is that ground balls cannot clear the fences for a home run. When we consider what we learned a few weeks ago in our HR/FB article – that pitchers cannot control the rate at which they allow home runs – logically, we can assume that the higher percentage of ground balls a pitcher gives up, the lower percentage of home runs he will give up.

Check out this list of pitchers from 2007 who threw at least 210 innings:


As you can see, the guys with the highest ground ball rates gives up far fewer home runs per ball in play than those with lower ground ball rates, even if their other skills are good.

Take a look at the name at the top of the list. Johan Santana gave up more homers per ball in play than anyone on this list, despite being one of the most skilled pitchers in baseball in terms of strikeouts and walks. The bottom line is that home runs are more closely tied to a pitcher’s groundball rate than with any other meaningful statistic.

Getting ground balls isn’t all daisies, though. You need to consider that ground balls are, still, balls in play, and that a pitcher relies upon his defense to ultimately turn it into an out. A strikeout is much more preferable. Furthermore, ground balls actually become hits on balls in play more often than fly balls do.


*All ground balls are balls in play, so “BA on GB” would be the same as “BABIP on GB.”

When you include home runs, though, as we did in the third column, we see that there are slightly fewer ground ball hits than fly ball hits. Even better is that none of those ground ball hits are home runs.

As you can see, ground ball rate is an extremely useful stat. Still, you need to make sure you keep it in the right context. Ground ball rate alone is not enough to qualify a pitcher as a worthy target for your fantasy team. You need to check his other skills, primarily strikeouts and walks, before making a decision. Check out these tables, showing pitchers ERAs. Data is taken from 2004-2007 among pitchers with at least 50 innings pitched.


As you can see, independent of the pitcher’s strikeout or walk rate, a high ground ball rate will provide a better ERA than a low ground ball rate. Without a good strikeout or walk rate, though, it won’t matter much, because a 4.53 ERA isn’t something to chase in most fantasy leagues.

What you need to do is find pitchers with high ground ball rates and either 1) a good strikeout or 2) a good walk rate. If you can find a pitcher with all three you’re in great shape, but there are only a handful of pitchers who possess all three skills.

Let’s check out the pitchers from 2007 who had at least a 50% ground ball rate and either a K/9 greater than 6.50 or a BB/9 lower than 2.25.


You’ve probably already realized that most of these guys are good, but you might not have been thinking about Greg Maddux, Derek Lowe, Dustin McGowan, or Chad Gaudin as 2008 targets. Knowing what you do know, though, I bet they seem a lot more appealing, don’t they?

If we change our criteria to pitchers with a 50% ground ball rate, K/9 rate greater than 6.50, and a BB/9 lower than 2.25, we don’t find any pitchers meeting the criteria in 2007.

From 2004-2006, just 3 different pitchers met the criteria. Chris Carpenter did it in all three years, Brandon Webb did in 2006, and Roy Halladay did in 2005. Obviously, if you notice a pitcher do this in the future, he’s a guy you’re going to want to target.