Digging into Hyun Jin Ryu’s recent struggles

Paul Berthelot
2 years ago
Hyun Jin Ryu has been struggling here down the stretch.
Over his last eight starts, he’s pitched to an 8.10 ERA, giving up seven runs in three separate starts. In four starts he failed to make it past the fourth inning.
He’s been putting the team in early deficits and putting more pressure on the bullpen to cover more innings. It hasn’t all been bad for Ryu he did have a couple of good starts in this stretch, shutting out Detroit over seven innings on August 21st, and then shutting down the Yankees over six on September 6th. However his last two starts against Baltimore and Minnesota he gave up 12 runs over 4.1 innings.
For a team in a tight playoff race, you can’t afford to keep pitching Ryu and see if he will figure it out. The Blue Jays have given him a chance to reset and placed Ryu on the 10-day injured list with a strained neck.
When a pitcher like Ryu has stretches like this it’s usually tied to his velocity. Ryu for his career has much more success when his fastball is averaging above 90 miles per hour. His two best starts in this stretch, the Tigers and Yankee starts mentioned above, Ryu averaged 91 with the fastball. Velocity hasn’t been the problem.
 Apr 1 – Aug 3Aug 8 – Sept 17Difference
We’re not talking about sizable increases but his velocity has been up on all his pitches.
The other obvious theory would be Ryu was affected by the sticky stuff crackdown in June and saw the spin rate drop on his pitches. Again though this doesn’t appear to be the case, Ryu’s spin rates have remained consistent all season.
What’s really been the issue for Ryu has been his control. The old baseball adage doesn’t matter how hard you throw if you can locate it well. Ryu built his whole career on this. He could pinpoint the ball exactly where he wanted, right on the edge of the strike zone.  During this rough patch we have seen too many pitches like this:
That curveball is a hanger and not something we normally see from Ryu. The curve has been a problem. He’s thrown the pitch 12.4% of the time during this stretch and batters have hit .500 off it with a 1.250 slugging percentage. Location of the pitch has been well off where it was earlier in the season.
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This is a theme will all his pitches.
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Seeing these heat maps it should come as no surprise that Ryu’s hard-hit rate is up 10%. There are far too many pitches in the strike zone, and hitters are recognizing this and being more aggressive on those, while chasing less out of the zone. Ryu is still striking batters out, but he’s walking a batter more per nine, and the extra hard contact he’s allowing has led to more balls leaving the yard. He’s allowed eight homers in these eight starts, after allowing just 14 in his first 21 starts.
You’ll notice Ryu seems to be throwing more pitches up in the zone, which is not something he should be doing. That could mean there is something off mechanically. Looking at the video his mechanics, position on the mound and his arm slot all look to be the same. Nothing has shown up in the data either. His release point and extension have remained consistent all season. If there is something, even small, off the Blue Jays coaching staff will all the information they have surely will be able to find it.
The other potential concern with Ryu is you have to wonder if he is tipping his pitches. He seems to get through the first couple innings, or once through the batting order ok. Then unravels after that. Again though this doesn’t seem likely, you would think someone by this point would have noticed. Nate Pearson was tipping his pitches in Tampa and Joe Siddall was all over it.
Personally, I think Ryu has become far too predictable and batters are able to sit on a certain pitch knowing that at some point in the at-bat they are going to see that pitch in the strike zone. Ryu is a pitcher who has a wide arsenal and keeps hitters off-balance with a variety of pitches. In 2020 Ryu threw five different pitches at least 10% of the time and none more than 30%. This season he scraped his sinker, a pitch he threw 10.6%, in favor of more four-seamers. He is throwing his fastball 35.9% of the time this season, the second-highest rate of his career. And during these last eight starts, it’s up to 40%.
Ryu’s fastball was great early in the season. Per Baseball Savant, it was worth -3.7 runs over his first 21 starts, his most valuable pitch. In the last eight starts though it has a run value of 3.5 his second-worst pitch behind the cutter. He’s throwing his fastball and cutter a combined 65% of the time, and more often than not those pitches are in the upper third of the strike zone. This makes it very easy for the hitter. Ryu doesn’t have the elite velocity or the high spin rate to live at the top of the zone like that.
When Ryu returns from the IL he needs to change something. Whether that’s his pitch mix going back to a more balanced attack or mixing in another pitch like his sinker. The 10 days off will give Ryu the opportunity to reset and give him some extra rest. Ryu has pitched a ton this season; his next start will tie his career-high. The 159.2 innings he’s thrown are the third-most in a season. All this, after making just 12 starts and 67.0 innings in the shortened 2020 season. It’s very possible Ryu is just worn out from the long season. The playoff race is coming right down to the wire hopefully Ryu can come back after 10 days and give the Blue Jays one more good start.

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