One of the beauties of baseball as an analytical pursuit is that there's a record kept of pretty much everything. What we've all been familiar with from our young ages are the records of results, or statistics, like dingers or ERA. What we've only more recently gained access to, though, are records of processes, the factors that to some extent determine or respond to the results. Considering the processes opens up a whole new layer of potential analysis, as you can see not just what happened, but why it happened, and what has or hasn't been done about it.
Myself, I like to look at how players get pitched. I'm still getting used to the fact that I can look at this at all, and I think it's fascinating to basically see evidence of the scouting reports. It's readily evident that, say, pitchers don't want to throw Josh Hamilton fastballs in the zone, because they don't need to. It's readily evident, as well, that pitchers are perfectly happy to be aggressive with Ben Revere, because, why not? Certain guys get pitched in certain ways, and there's a broad spread between the extremes. And more often than not, scouting reports and approaches will hold consistent from year to year. Weaknesses tend to stay weaknesses, and strengths tend to stay strengths.
So given the consistency of this kind of data, it's interesting to look at the cases where the numbers change. If the changes are big enough, it stands to reason the changes aren't accidental. This all builds to the question: who's been pitched the most differently in 2014, relative to 2013? This isn't something we could've easily played with in 2004. In 2014, the information's out there for anyone.
Of course, pitching approaches are complex, and analysis is best and most consumable when it's simple, so I'm going to use a proxy here. I'm going to look at players' rates of fastballs seen in or just outside of the strike zone. That can tell us a lot, even if it can't tell us everything, and between 2013 and 2014, I'm using pitch minimums of 1,000. There are 226 hitters who saw at least 1,000 pitches in each of the last two seasons. The average rate of ~zone fastballs has been roughly 40%, and between years for each player, the correlation (r) is 0.84. The minimum has been about 28 percent; the maximum has been about 51 percent.
Let's look at two sets of five extreme players. To start with, here are the five players who've seen the biggest increases in fastball rate within or near the zone:
| Player | 2013 Rate | 2014 Rate | Change |
|---|---|---|---|
| Kelly Johnson | 34.9% | 40.6% | 5.7% |
| Daniel Nava | 41.6% | 46.3% | 4.7% |
| Yasiel Puig | 31.4% | 36.1% | 4.7% |
| Miguel Cabrera | 35.8% | 40.5% | 4.7% |
| Allen Craig | 37.6% | 42.2% | 4.6% |
It's probably not very interesting to see Kelly Johnson on top of the list, but there are some really significant names in there, getting pitched more aggressively in 2014. For Johnson, this is probably a combination of age and a lack of fear. While he was a semi-productive hitter a year ago with the Rays, this season he wasn't hunting fastballs the same, and there's also the matter of pitchers not wanting to give him something to pull as a lefty in Yankee Stadium. Johnson's power outside of Yankee Stadium, or to other fields, is super limited.
Nava a year ago was a good hitter across the board. Yet, while he's a contact hitter and a line-drive hitter, he's also got just four home runs in nearly 400 plate appearances, so pitchers have been content to be more aggressive. Generally, pitchers are willing to stay around the zone if they figure they're at little risk of giving up extra bases.
With Puig, I think there are two explanations. When he fell into a slump, not too long ago, he was having trouble with heat, rolling over on a lot of fastballs. But also, this year, Puig has had a much more disciplined approach at the plate, significantly cutting down on his out-of-zone swings. So with Puig less willing to chase secondary stuff up or in the dirt, there's been less to gain from throwing those pitches, and pitchers have had to come after Puig more often.
It's no secret that Cabrera's been playing hurt. He started the year with his timing off following offseason surgery, and over the course of the season he's developed a handful of aches and pains that have on occasion left him limping. Cabrera has less available force at the plate, and while he's still an extremely dangerous hitter, he can be a little more exposed with good fastballs. Between 2010-2013, Cabrera slugged .640 against heat. This year, he's at .515, while he's still driving softer stuff. This is a version of Cabrera with a vulnerability.
And there's Craig. Craig appears to be a case of missing bat speed, possibly -- hopefully -- due to a lingering injury. But because of whatever reason, Craig has just about lost left field, as he's proven less capable of turning on the ball. Noticing that, pitchers have worked Craig harder and harder, and he hasn't caught up. A year ago, according to FanGraphs, Craig was 26 runs better than average hitting fastballs. This year, he's been ten runs worse than average. If it's not injury, it's even worse news.
And now, here are the five players who've seen the biggest decreases in fastball rate within or near the zone:
| Player | 2013 Rate | 2014 Rate | Change |
|---|---|---|---|
| Alejandro De Aza | 43.0% | 36.8% | -6.2% |
| J.D. Martinez | 39.5% | 33.9% | -5.6% |
| Lorenzo Cain | 42.6% | 37.4% | -5.2% |
| Michael Bourn | 43.9% | 38.8% | -5.0% |
| Skip Schumaker | 43.9% | 39.0% | -4.9% |
You're not here to read about Skip Schumaker, and I'm not here to write about Skip Schumaker. Schumaker's in that table. Okay. We can address the others. I'll note that, right behind Schumaker, there's Victor Martinez, with a change of -4.7%. That makes good sense -- offensively speaking, Martinez has been on another planet. Of course pitchers have wanted to be less aggressive with him.
With De Aza, it's just strange it took this long to see something of an adjustment. De Aza's long been mostly a fastball hitter, and a year ago, fastballs accounted for 85% of his extra-base hits. So this year, he's seen fewer fastballs, and he's slugging under .400 for the first time as a regular. He has so far hit well as an Oriole, but then, so far as an Oriole, he's also seen more fastballs, against potentially less-familiar opposition.
Martinez is easy to explain. See, this year, Martinez has broken out, hitting for power to all three fields. By changing his swing, Martinez has basically doubled his power output, and now he doesn't hit almost all his home runs to the pull side. So Martinez is a guy pitchers have to take seriously as a threat in the middle of the Tigers' order, so he's getting pitched like swing-happy threats get pitched. He swings and misses a lot, but he also hits the ball hard a lot.
Cain for the first time has put fear in some minds. He's not a power hitter, but he's hit .366 against hard stuff, and just .219 against softer stuff. He's made himself more aggressive against fastballs, but he's also swinging more often at non-fastballs, demonstrating a willingness to chase, so pitchers have tried to get Cain to swing at moving pitches more often. Because Cain's hitting .304 overall, things are working only so well, but then he does have four times as many strikeouts as walks so these numbers might not be sustainable.
And, Bourn. This is easy -- Bourn's been a fastball hunter. The last two years, he's been 20 runs above-average against fastballs, and 22 runs below-average against non-fastballs. Last year, Bourn batted .162 against non-fastballs; this year, he's batted .171. So Bourn has a clear weakness, and this season that's been taken more advantage of. He's at least done well with the fastballs he's seen, but it seems he'll see those in lesser numbers.
So that's just one of the ways in which we can analyze the processes. And as such, that's one of the ways in which we can do something to get inside the players' heads. We've long known which players were good and which players were less good. At least equally interesting are the scouting reports. We'll never quite know all those reports, but we can dig and infer. One of the best parts of baseball is the digging.
