Was Hyun-Jin Ryu’s Changeup the Most Effective of 2019?

What actually makes a pitch effective? Is it the ability to induce whiffs or draw weak contact on a regular basis? Both? Are those factors actually the result of the pitch itself or the way others in a repertoire set it up? How about its movement? Can that alone make a pitch great?

Changeups and sliders are both interesting pitches, sliders in particular because there are so many variations. And changeups can be thrown with a variety of grips, making them all behave in different ways. The circle change, the Vulcan change, the “Fosh” change, the three-finger and split change — the list goes on.

Luis Castillo, Kyle Hendricks, Mike Minor, and Zack Greinke are a few pitchers who possess a great changeup. But there is another you might not think of in the same breath who deserves the same level of recognition. One that Pitch Info rated as having the most effective changeup in baseball through the 2019 season, namely former Los Angeles Dodgers starter and current free agent Hyun-Jin Ryu.

Before we dive into Ryu’s changeup, let’s go over what having an “effective” changeup, per Pitch Info, entails.

This evaluation of effectiveness comes from our Pitch Type Linear Weights (or ‘Pitch Values’), which attempt to measure how successful a pitcher (or hitter) has been with (or against) a particular pitch. Did batters regularly hit the pitch for productive outcomes, or does it tend to create outs? There is no real predictive value in these ratings. Instead, they are a reflection of what happened over the course of the season, which makes this stat particularly useful here.

A bit of caution, as there is some missing context here. If a pitcher throws a highly-graded pitch, it doesn’t always mean that it’s been strong across the board. A pitcher could have other pitches that make the pitch in question better. For example, maybe he has a dynamite fastball and a breaking pitch that, when thrown before or after the heater, regularly keeps the hitter off-balance and produces favorable results. Is it because of the pitch itself (in this case, the changeup) or is it an after-effect of the fastball? Is Ryu’s changeup elite because it’s a good pitch on its own, or because his fastballs complement it well?

For this article, we’ll scale to 100 (wCH/C) since pitchers throw the changeup varying amounts and we want to level the playing field to get a better, and hopefully more accurate, perspective. The changeup value chart below features pitchers who threw at least 80 innings and used the changeup at least 20% of the time in 2019:

Let’s talk about some basics of Ryu’s changeup design. In 2019, he threw the pitch with an average (estimated) spin axis of 112-degrees at roughly 80 mph (6% below average) and a 1487 rpm spin rate (18% below average). This movement profile created a pitch shape that produced a 7.5 CH-X (horizontal break) and a 2.3 CH-Z (vertical break).

Observe the pitch, up close, in action:

I want to dig a little deeper into some 2019 changeup data, so I’ll reference Andrew Chamberlain’s useful Pitch Leaderboard chart. Ryu’s wOBA on contact (.257) is second only to Mike Minor’s (minimum 500 pitches and more than 20% usage rate). Over half of Ryu’s contact on the changeup produced groundballs, which places him 18th overall (minimum 80 IP) in GB+ (more on FanGraphs’ “Plus” metrics here). On groundball contact, Ryu had the 12th lowest wOBA of pitchers with at least 25 batted ball events on the changeup.

 

There are other facets of the game besides the pitcher himself that can influence pitch outcomes, like generous or stingy umpires, or a catcher who excels or falters as a pitch framer. 44% of Ryu’s changeups were thrown in the shadow of the zone, the areas immediately inside or outside of the strike zone. Was he able to get framing help from his battery-mates? His main catcher, veteran Russell Martin, who ranks 11th in our framing metric (min 400 innings), helped Ryu “steal” 17 strikes on his changeup in 2019, which is 27% of his overall called strikes. It wasn’t a big factor, but it definitely helped.

Regardless, Ryu drew a pretty high chase rate (56%) on his changeup this year, overwhelmingly against righties (87%). Here’s a look at his changeup whiff heatmap:

Another factor that made Ryu’s changeup so effective was how he mixed his pitches under particular circumstances. Ryu used his changeup almost as much as his fastballs when ahead in the count. He most regularly used it against righties and most often went to the pitch against left-handed hitters to draw a strike when the hitter was ahead (26%) and when he was up to two strikes (29%):

What’s interesting about this chart is that there aren’t any obvious giveaways as to when he’ll throw which pitch. His velocity spreads are also strong, with his fastballs (four-seam, sinker, cutter) floating around the high 80s/low 90s, his curveball in the low 70s, and the change averaging 80 mph. With his ability to mix pitches and his velocity range, Ryu can keep hitters off-balance without having to overpower them or create any sort of set-up pitches.

The pitch that Ryu plays off his changeup the most often is the four-seamer, followed by the cutter and then a curveball. We’ll use Baseball Prospectus’ tunneling data (PreMax and PlatePreRatio) to see if there’s an additional layer of deception Ryu uses to create a stronger changeup. All combos present have been thrown at least five times.

These small samples are the result of Ryu not always following a pattern hitter-to-hitter, so the metrics within shouldn’t be considered totally reliable, but they still give us a good idea as to how hard it is to pick up his changeup off the two other pitches he most often matches it with. The spin direction on his changeup and fastball are somewhat close (maybe a 30-degree separation), but it’s hard to tell based on this small a sample if it adds an additional layer of deception.

It would appear that the fastball to changeup works best against lefties, as they tend to be pretty close at the tunnel point, with an above-average ratio spread at the plate. To righties, the cutter to changeup works pretty well, and has a bit larger of a ratio spread from the tunnel point than his fastball/changeup sequence to lefties. His four-seamer and change have a very similar horizontal break, with the latter dropping.

After receiving and accepting a qualifying offer last offseason, Ryu can’t receive another, and will hit the market without the hinderance of his signing team having to give up draft pick compensation. Given the size of the contract he’s likely to garner, it seems unlikely that he’ll return to Los Angeles. Every major league team is after starting pitching in some capacity; Ryu’s injury history might make him a bit less of a draw than other more high profile options this winter, but after capturing the ERA title and posting a FIP in the low threes, Ryu should still receive significant interest this offseason (he ranked 13th on our Top 50 Free Agent list). With his elite changeup in tow, along with his ability to keep hitters on their toes, the team that signs Ryu could end up with a front-line starter to anchor a rotation in need of an immediate boost.