The Response to Matt Kemp

A friend of mine who dropped out of a chemistry PhD program would describe the experience as getting to know more and more about less and less until you know everything about nothing. There’s a lesson in there about the nature of limits, but there’s also the comparison between general knowledge and specialization. I feel like my writing has taken me on something of a PhD course, where I used to write about simpler things, and now I have to keep digging deeper and deeper to find new deposits worth mining. One of my current fascinations is the interplay between pitcher and batter, the strategy of sequencing, and I just wrote about that for Fox. In that piece, I talk about players who’ve been pitched differently in 2014, relative to 2013.

As a natural follow-up, I figured I’d look at players who’ve been pitched differently within 2014, say, splitting the first and the second halves. I did all the research and I generated all my numbers, but when I evaluated them, I decided I’d focus on one player in particular. You’re already aware that Matt Kemp is experiencing a major resurgence at the plate. Mike Petriello wrote about him earlier this very month. And how have pitchers responded to Kemp’s incredible rebound? Relative to the season’s first half, no player in baseball has had a bigger drop in his rate of fastballs seen in the vicinity of the strike zone.

The data comes from Baseball Savant, and by “vicinity of the strike zone”, I’m describing a box the size of the strike zone, but also a little bigger at the edges. In the first half, about 40% of the pitches to Kemp were fastball varieties in or near the zone. In the second half, about 32% of the pitches to Kemp have been fastball varieties in or near the zone. It’s a drop of eight percentage points, but it’s also a drop of 20%, pushing second-half Kemp near the league minimums. It’s been the biggest drop in baseball by a fair margin, and prior to this year, Kemp’s ordinary rate was around 37%.

Here now is a 2014 month-by-month comparison between Kemp’s rate and the rate seen by the rest of his Dodgers teammates:

Kemp started to pull away a little bit in July. The last two months, there’s been a double-digit separation between Kemp’s rate and the rest of the Dodgers’ rate. This appears to be evidence of a conscious decision to throw Kemp less hittable hard stuff. It correlates well with his hot streak.

So: why? Here’s an easy way to explain. An average big-league fastball is about 92 miles per hour. This year in the first half, against pitches at least 92mph, Kemp slugged .448. In the second half, against the same pitches, he’s slugged .698. But no, that isn’t quite good enough. Or, it’s not convincing enough. Kemp, rather suddenly, has shown an ability to turn on fast pitches and drive them to left. Again, using Baseball Savant, let’s run some numbers. As the numerator: fastballs hit to left field, at least 300 feet. As the denominator: all fastballs hit into play. We can go back to 2008.

• 2008: 4.9%
• 2009: 5.9%
• 2010: 4.5%
• 2011: 7.0%
• 2012: 1.9%
• 2013: 3.0%
• 2014: 7.3%

Kemp’s always been able to spray the ball around, and he was a hell of a hitter in 2012, but he was also a hell of a hitter in 2011. That’s the last time he showed this kind of pull power. And to break it down further, let’s look at just 2014. Kemp’s hit 19 fastball to left field at least 300 feet. Here’s when they happened:

• April: 2
• May: 0
• June: 3
• July: 1
• August: 9
• September: 4

That’s 14 of 19 since the All-Star break, and 13 of 19 since the beginning of August. From Brooks Baseball, Kemp’s first- and second-half spray charts, broken down by general pitch type (first half on the left):

Black dots are balls in play against hard pitches, and you can see that cluster on the right, to left or left-center field. He’s still able to drive the ball up the middle and to right-center, but now he’s able to hit the ball hard to all fields, which is a difficult thing for any hitter to pull off.

Why the turnaround? As Petriello linked to, Kemp did make changes right after the All-Star break, after approaching his hitting coaches. John Valentin and Mark McGwire almost immediately got Kemp to adjust his stance and stride, and while the changes are kind of subtle, these sorts of changes are always subtle, and one of Valentin’s proclamations has come true:

“He actually has straightened his stance,” Valentin said. “It used to be locked. What that created was a difficulty to have the freedom to stay through the baseball. This offers a clear path to hit balls in and away.”

Kemp, heater, early:

Kemp, heater, later on:

Kemp, heater, later on as well:

That last .gif is to show that Kemp isn’t just hunting fastballs he can drive toward left-center. Recently he’s just been more complete, and pitchers have caught on to the fact that good fastballs might be punished. At his career best, Kemp was among the premier fastball hitters in the league. As accumulating injuries took their accumulating toll, Kemp’s productivity against fastballs declined, and pitchers will always default to fastballs unless they have a reason not to. Recently they’ve been given a reason not to. So, since the start of August, only Victor Martinez has seen a lower rate of fastballs around the zone. Pitchers are trying to get Kemp out in other ways.

I don’t know if Kemp has actually fully recovered from his shoulder problems. Dan Farnsworth figures Kemp’s swing is still a little different, and he knows a lot more than I do. But even if Kemp won’t ever swing like he did in 2011, it seems he’s at least found a way to compensate, a way to get to pitches he wasn’t getting to for quite some time. In that way, Matt Kemp is producing like prime Matt Kemp, even if this version is getting there a little differently. Kemp’s a terror again, and pitchers are treating him like a terror again. As far as I’m concerned, there’s beauty in the fact of Kemp’s statistical resurgence, and there’s just as much beauty in the details.