The Pirates had reportedly made re-signing Francisco Liriano their top priority, and on Tuesday they officially got it done, with Liriano returning for three years and $39 million. Dave wrote a little thing earlier and concluded it was a pretty good deal, as these things go. Here is that little thing. Okay, great, we’re done here!

If it’s analysis of the move you want, it’s pretty simple and Dave touched on the major points. Nothing involving Francisco Liriano could be described as low-risk, but the terms themselves aren’t too risky. Liriano’s effective when he pitches, and he hasn’t actually had an arm problem related to pitching since 2011. Last year he went on the DL with an oblique strain. The year before, he had an arm fracture after taking a fall. These aren’t good things, but Liriano probably isn’t as fragile as his reputation. He misses bats, he likes being in Pittsburgh, and the Pirates had a need. There’s not really anything not to like, here.

Yet perhaps you want to know more about Liriano. He came to the Pirates labeled as an intriguing but frustrating live arm, with stuff and poor location. He still isn’t particularly stingy with the walks, but he’s been able to push himself over a hump, getting to the other side of tolerability, and a whole lot of it has to do with his changeup. The Pirates love what Liriano’s done with his changeup.

I’m not sure you actually need to know more than the following. Very simply, here are chase rates against Liriano’s changeup, year by year:

2011: 31% O-Swing% vs. changeup

31% O-Swing% vs. changeup 2012: 32%

32% 2013: 45%

45% 2014: 47%

The last two seasons, 158 starting pitchers have thrown at least 150 innings. Liriano ranks dead last in rate of pitches thrown within the strike zone. What that suggests is wildness, but, there’s more to the picture. Liriano also ranks in the top ten in chase rate, so now you dismiss wildness, and consider deception and unhittability. Liriano is No. 1 in lowest contact rate allowed. It’s not that Liriano can’t pitch in the strike zone; it’s that hitters haven’t forced him to.

The breaking ball, of course, is there. It’s the breaking ball that first made Liriano famous. But the changeup has turned into an incredible, reliable weapon. Consider, if you might, that the changeup is basically just a weapon Liriano uses against righties. Between 2011 – 2012, righties hit Liriano to the tune of a .336 wOBA. The last two seasons, that’s dropped to .297. The explanation for these things tends to come down to “improved mechanical consistency,” and that’s the case here. Ray Searage worked with Liriano on tweaks, Liriano folded them in, and by doing so they were able to unlock a pitch Liriano could use in any situation.

Clint Hurdle, from last September:

Hurdle said that part of what makes Liriano’s changeup so important this year is his command of the pitch, which allows him to throw it in any count, thus getting hitters off his fastball. “The counts he is able to throw it in is what makes a very solid but average fastball velocity-wise, play even bigger,” Hurdle said. “He can throw [the change in] a 2-0 count, 3-2 count, [which creates a] a different dynamic at the plate.”

Brooks Baseball makes this pretty easy to research. A couple relevant splits:

Liriano ahead in count, RHB

2011 – 2012: 27% changeups

27% changeups 2013 – 2014: 31%

Liriano behind in count, RHB

2011 – 2012: 18% changeups

18% changeups 2013 – 2014: 31%

The second split is the dramatic split. Liriano has greatly increased his changeup usage in what would be hitter-friendly counts, and the best explanation for that is Liriano has simply improved his changeup. With hitters looking for fastballs, the changeup catches them off balance, and because they’re already geared up to swing there’s not much they can do if a pitch comes in slower than expected.

From Baseball Savant, we can play with some changeup heat maps. From these, you’ll get an idea of what better command looks like. Let’s start with the less dramatic .gif. Here are Liriano changeups in pitcher-friendly counts.

You pretty much always want the pitch in the low-away quadrant. Liriano used it fairly well in 2011 – 2012, but the last two years you see a little more consistency down and away, off the plate. Fewer changeups appear to be toward the middle of the plate. Here are some chase rates:

2011 – 2012: 47% O-Swing%

47% O-Swing% 2013 – 2014: 53%

Now, that’s subtle. This is less subtle. Here are changeups in hitter-friendly counts.

There’s a substantial drop. If I were to simplify things, I’d say you’re looking at the difference between hung changeups and executed changeups. Now, that’s too easy, but you’re seeing a better ability to locate down, yet still within or near to the zone boundaries. Remember, these are hitter-friendly counts, so Liriano also wants to be able to maybe get a called strike if the hitter lays off. The chase rates:

2011 – 2012: 25% O-Swing%

25% O-Swing% 2013 – 2014: 43%

That’s huge. That’s a pitch that gets hitters off balance, because they don’t expect it, because they don’t read it, and because the pitches end up in good spots. When hitters increasingly have to respect the changeup, it keeps them off the fastball in fastball situations. And the swings out of the zone also allow for Liriano to fight back from more counts. He hasn’t become a strike-thrower. He hasn’t become a Cliff Lee. But Liriano’s strikes have gone up enough. He has a better ratio of pitches thrown ahead in the count to pitches thrown behind in the count. When you miss bats and get grounders, you have to achieve only a low threshold of strike-throwing. Liriano has met that threshold in Pittsburgh, and it’s clear the Pirates believe he’ll continue to do so for at least another few years.

Liriano was worse in 2014 than he was in 2013. On the other hand, he was better in the second half of 2014 than he was in the first half of 2014, so it isn’t as simple as saying he took a step backward. He seems to be, when he pitches, an above-average pitcher, who gets a lot of swings and misses, and he hasn’t gone on the DL with a worrisome arm problem in a while. For the Pirates, Liriano is an appealing pitcher at an appealing rate. And Liriano stands as proof of the value of a quality changeup. The Pirates made that one pitch better, and Liriano’s final days in the American League are but a distant and fading memory.