From the case of Rich Hill, I’m not sure one could learn any lessons. For one thing, he still has more time to pitch, so his final chapters are unwritten. But even if Hill is already underwater, so what? No one needs to be told that there are risks inherent in committing to a free agent 37-year-old. And it’s not like anyone else is following the Rich Hill career path. His case is unique. What matters for him might not apply to anyone else. Everything about what he is is atypical, and so we stand to learn about Hill and Hill only.

It is fair to say, though, there are things to be learned. The Dodgers are probably anxious to learn them, because they’re counting on Hill, and he’s not pulling his weight. Now, no one thought Hill would throw 200 innings. I don’t think anyone expected 140. But here’s Hill now, at 35 innings after eight starts, eight starts in which he’s run up a 5+ ERA. Hill’s strikeouts have fallen and his walks have exploded, and Thursday in Cleveland saw him cough up seven runs. Rich Hill isn’t right, and although the Dodgers aren’t so worried about his June, they’d like to know if he’ll be fine by October. Something right now is borked up.

The problem is really as simple as this: Hill, a year ago, had 33 walks and 129 strikeouts. Hill now is at 23 and 35, respectively. What the Dodgers want to know is, what’s the root cause? We might as well start getting into that stuff. So here’s the first of two tables. I looked at starting pitcher four-seam velocity for 2016 and 2017. Here are the pitchers, so far, who have lost the most zip, on average:

That isn’t so much of a promising table. No pitcher really wants to lose velocity, and Hill didn’t even have that much to give. He’s been down by more than a tick and a half, and it’s tough to shrug that away. This, presumably, is at least a partial explanation for Hill’s problems. Maybe it’s everything! But there’s still more evidence to review. What I have now is a plot. On the x-axis, starting-pitcher changes in swing rate at pitches out of the zone. On the y-axis, changes in swing rate at pitches inside of the zone. Ideally, a pitcher would show up in the bottom-right quadrant. I’ve highlighted Rich Hill in yellow.

The best quadrant is the bottom-right. The worst quadrant is the upper-left. Rich Hill finds himself in the upper-left. His chase rate has gotten worse by four points, and his in-zone swing rate has gone in the wrong direction by five points, and it’s easy enough to blend the two. I’ve written before about how I like to subtract O-Swing% from Z-Swing%. Here are the starters who have declined the most in this sense, since 2016:

Hey, look, a whole bunch of Orioles! That’s how you know this isn’t good. Hill isn’t the worst, but he’s tied for eighth-worst out of 124. Hill has seemingly lost some of his deception. Hitters are more comfortable, taking better approaches, and that’s left Hill looking far more vulnerable.

Let’s watch a few select clips from Hill’s Thursday outing against the Indians. Here’s a fastball that got obliterated by Edwin Encarnacion:

Here’s a fastball that went for a bases-loaded walk to Roberto Perez:

Here’s a curveball that came just *before* the bases-loaded walk to Roberto Perez:

You’re looking at pitches up, and to the arm-side. Now, Hill is no stranger to throwing pitches up and to the arm-side, but now it’s gotten silly. Here are two plots, showing Hill’s pitch locations for 2016 and 2017. These are from the catcher’s perspective, so righties would be on the left, and lefties would be on the right.

Do you see that? Why don’t I-

This, I think, most captures the problem. I think this is the clearest sign that Hill is doing something wrong. He’s missing the zone up and arm-side an awful lot, and that’s making the hitters’ job easier. Baseball Savant groups all pitches into zones, and it has one particular zone that would roughly correspond to up and arm-side, out of the strike zone. Hill, in 2015, threw 16% of his pitches in that area. Hill, last year, again threw 16% of his pitches in that area. Hill, this year, has thrown 24% of his pitches in that area. Only Brian Johnson has a higher such rate among lefties, and there’s a five-point gap between second-place Hill and third-place Fernando Abad.

Why stop there? Here are Hill’s up and arm-side rates for fastballs:

2015: 14% fastballs out of the zone, up and arm-side

14% fastballs out of the zone, up and arm-side 2016: 16%

16% 2017: 24%

Here are Hill’s up and arm-side rates for curveballs:

2015: 13% curveballs out of the zone, up and arm-side

13% curveballs out of the zone, up and arm-side 2016: 15%

15% 2017: 23%

Hill’s leaving too many fastballs up and away. He’s also leaving too many curveballs up and away. Those are easier pitches for hitters to lay off, and they also inform the hitters that Hill is having trouble getting pitches down or in. So they can increasingly zero in on elevated strikes, which might help explain another trend of interest. Hill’s otherworldly curveball, this season, has a negative run value. Here are Hill’s curveball grounder rates:

2015: 64% grounders on the curve

64% grounders on the curve 2016: 60%

60% 2017: 38%

Batters are hitting the curve in the air. They’re not destroying it, but they’re making better decisions and applying better swings. That pitch has been less useful for Hill, which is a problem, given how often he prefers to throw it. The whole key has been throwing the curveball for reliable strikes. As Hill has struggled to finish pitches, he’s put hitters in more of an advantageous position.

Velocity down. Location off, mostly up and arm-side. It could be something subtle and mechanical, with Hill flying open, or alternatively throwing a little too much across his body. Other than that, you have to think about Hill’s blister issue. Hill has said recently that the blister problem hasn’t recurred, and there’s a good chance he’s telling the truth. Now, he might actually have some finger discomfort, which has prevented him from completing his pitches normally. Or it could be he’s just struggling to regain his normal feel for the ball, after having been sidelined for a few weeks. Hill has acknowledged how much of his own game comes down to having that proper feel, and it’s not something you can force. Hill’s whole approach involves subtle manipulation of grips and finger pressure, and he hasn’t settled into a groove.

If there’s good news, it’s not like Hill is getting blasted. So much of his issues come down to his walks, and hitters aren’t just teeing off. The other good news is it’s the middle of June, and the Dodgers, in theory, don’t need Hill at his best right now. They will, however, need him to be better. Rich Hill, by now, has probably earned the benefit of the doubt. At some point, however, he’s going to lose it.