Pitchers Went Up in 2017 and It Didn’t Work

Last May, Jeff Sullivan — along with others like this author and J.D. Martinez — hypothesized that pitchers might already be thinking about a way to adjust in the fly-ball era. The possible antidote? To work higher. After all, the swing changes that helped produce a surge in home runs were designed largely to address pitches at the bottom part of the zone, notably the growing number of two-seam fastballs directed there.

Said Martinez to this author last spring of how pitchers appeared to be adapting:

“Pitchers are countering it right now. The pitchers are always ahead,” Martinez said.

What exactly are the adjustments being made to his swing path? Martinez and I had not, apparently, reached that level of trust.

“That’s one of the things you don’t want to tell anyone,” Martinez said.

While Martinez would not reveal what he believes to be countermeasures to his swing path, it appears pitchers are trying to elevate their fastballs against Martinez.

The home-run surge — whether a function of the changing ball, evolving swing planes across the league, or a combination of factors — began in the second half of 2015 and has since, of course, continued. Jeff found that, in the second half of 2015 and 2016, the increase in home-run damage done by batters had largely occurred in the bottom half of the zone. So it made sense that pitchers, especially those with high-spin fastballs with a rising effect, would turn their attention upwards.

Pitchers like Jake Odorizzi, for example. It was Odorizzi who told this author last spring that he had become more committed to a high-fastball approach. The numbers bear that out: the right-hander utilized the high fastball more than ever last season. Of course, Odorizzi also allowed 30 home runs in 143 innings.

Odorizzi’s 2017 campaign led me to a pair of questions. First of all, were pitchers working up in the zone more frequently last season? And if so, was it working?

With regard to the first question, the answer is “yes.” According to Baseball Savant’s “detailed” zone, pitchers threw 40,937 four-seam fastballs in 2016 that crossed the plate either in the upper-third of the zone or the 50-50 borderline area at the top of it. In 2017, that number increased to 46,193 — or, by roughly 5,000 pitches.

Of course, using Baseball Savant is problematic when comparing data from 2017 to the period before it. Pitch data from 2008-16 was captured by PITCHf/x, while use of the Statcast system began last season. The systems sometimes categorize pitches differently.

To eliminate some of the differences between PITCHf/x and Statcast, I decided to examine month-by-month data from PITCHf/x in 2016 and Savant data from last season. I was curious to see if there were any notable changes within a given season. There were! Consider the HR/swing percentages in the following chart….

It appears that, as the 2017 season progressed, batters become a little less adept at homering on the low pitch but were better able to crush pitches in the upper-third of the zone — even as pitchers targeted that area more often. The home-run surge was quite possibly the product of batters not only adjusting but doing so at record speed.

So perhaps the problem for a pitcher like Odorizzi last season was that batters knew exactly where to look. Perhaps major-league batters were zeroing in. And, of course, the elevated pitch has always been easier to elevate and drive than the low pitch, so it doesn’t require swing-plane changes to be effective. The high four-seam fastball naturally leads to an air ball more often than a lower pitch will.

Who benefited the most? According to the Statcast data, 17 players hit 10 or more home runs on pitches in the upper-third of the zone.

According to PITCHf/x data, only seven batters did that in 2016. In 2013 (Kyle Seager) and in 2014 (Paul Goldschmidt), only one batter each reached that same threshold.

Here are the total volume of home runs hit by zone over the last two seasons:

While the following table is a blend of PITCHf/x (2015-16) and Savant data (2017), it again indicates batters were better able to damage the high pitch by multiple different indicators:

While the divide between PITCHf/x and Stacast data renders the evaluation of pre-2017 and post-2017 numbers difficult, there nevertheless appears to have been greater damage done on the high pitch on a month-by-month basis in 2017 alone.

Because they possess the ball and dictate the action, pitchers will always remain a step ahead of batters — although, as Martinez notes, the latter group appears to be adjusting faster than ever to keep pace. It might be difficult to find a cure for the home run.