Should We Be Worried about Homers against Clayton Kershaw?

In a Word: No.

It’s true that he’s already allowed more home runs this year (11) than he did all of last year (9). It’s also true that his home runs allowed per 9 innings (0.99) is his highest since 2008 (0.92).

But, as frustrating as these numbers are, we should remember what the research tells us: although pitchers have some degree of control over the types of batted balls that they allow, they can do less about whether fly balls leave the park. Based on this insight, we have reason to keep Kershaw’s results in perspective.

Let’s take a look at the three critical factors that Jeff Wiser identified last year in profiling HR-prone pitchers:

1. HR/FB Ratio

It’s insufficient to cite Kershaw’s home run numbers without also looking at his fly ball rate. On the latter front, he’s around 25% — a top-15 showing. It’s also approximately 4 percentage points lower than last year and 10 percentage points below his career mark.

When the fly balls are set against the context of home runs, we see that Kershaw’s HR/FB ratio is 18%. That ranks among the highest in the league. More notably, it’s way off his career average of 7% and the “reasonable” range of 8%-12% for a typical pitcher, which strongly suggests bad luck. That’s unlikely to continue at such an alarming pace.

2. Strikeout Rate

If Kershaw weren’t missing bats, then #1 would be potentially problematic. But, in fact, his strikeout rate is strong. At 33%, it’s a tick higher than last season, and it’s above his career 27%. That bodes well for his overall performance, including against the long ball.

3. Groundball Rate

Kershaw’s grounders are on par with last year’s mark of 52%, which saw an improvement over his career average in the mid-40%. He ranks in the top 25.


Of course, nothing’s perfect, and Kershaw has some red flags. For example, his line-drive rate is higher than last year, as is his hard-hit rate. We should definitely keep an eye on these metrics as the season progresses.

But, overall, if we look at his 2.18 xFIP and the three factors above, there’s reason to believe that Kershaw’s home run numbers will eventually return to normal.