Hyun-Jin Ryu’s Other New Toy


After Hyun-jin Ryu‘s excellent start on Sunday evening, his curveball got attention here and elsewhere. Sunday’s start was Ryu’s first of the year in front of a Pitch F/X system, so I went to Brooks Baseball to look up more information on the curve. However, while researching, I stumbled on something else that was interesting. The curveball wasn’t only different pitch for Ryu. According to the data, Ryu has added a sinker (the pitch could also be a two-seam fastball, since Brooks often groups the two pitches together).

According to Brooks, Ryu threw the sinker 14 times on Sunday, or 16% of his 86 total pitches. Before that start, he had never thrown the pitch. He didn’t use the sinker very often while ahead in the count, instead using it more often while behind or even in the count.

The break on the pitch is very interesting:


The sinker basically breaks the same as his change-up but at 91MPH. In concept, that sounds great. If the break is similar, it could potentially fool batters into thinking that the sinker is a change (or vice versa). If that’s true, the pitch could be a valuable addition to Ryu’s arsenal.

I decided to search Baseball Prospectus’ Pitch F/X leaderboards for comparable sinkers in 2013. The closest option I could come up with was Wei-Yin Chen, who throws his sinker at approximately the same speed and same break as Ryu’s. Chen is about a league-average pitcher, but his sinker hasn’t had great results. He allowed a line drive rate of 27% on the pitch and a SLG of .500 in 2013, neither of which are great. However, break doesn’t describe the full value of a pitch and Ryu might have the added benefit of deception.

After digging into the specifics Ryu’s sinker, there’s some reasons to be concerned. First of all, he tended to leave the pitch up:


He also only generated one swing and miss on the pitch, far less than what is ideal. Here’s a GIF of the pitch doing its job, however:

GIF Link

It’s a bit early to get excited about Ryu’s sinker. Half of them came in the first inning, while he was struggling with his command. He threw seven more while he was pitching well. The sinker could just be an aberration in the Pitch F/X data. It’s definitely worth keeping an eye on Ryu (and the accompanying data) to see if he keeps using the pitch, and to monitor his success with it.

About Daniel Brim

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Daniel Brim grew up in the Los Angeles area but doesn't live there anymore. He still watches the Dodgers and writes about them sometimes.