Checking Hisashi Iwakuma

With news popping Sunday that right-hander Hisashi Iwakuma‘s sore knee will push back his start to Thursday in Toronto, it’s a good time to talk about the 36-year-old’s immediate future.

Iwakuma was solid a year ago, making 33 starts and covering 199 innings with a good-enough 4.27 FIP. Reliability is the name of Iwakuma’s game.

He averaged six innings per start, whiffed 17.6 percent of the batters he faced and walked just 5.5 percent. Iwakuma averaged 88.2 mph with his four-seam fastball for the year and was strong in September, sitting above 88 on the average in 5 of his final six outings — 88.8 on October 1, his very last start.

But that was 2016. The calendar has taken a turn and so has Iwakuma — for the worse.

Iwakuma has struggled for much of this season. Batters are lifting his pitches with more frequency, which means fewer ground balls.

As expected, the result is fewer outs in general and more extra-base hits allowed. Also as expected, it’s easy to see why Iwakuma has struggled to the tune of a 6.29 FIP, seven homers allowed and just two starts — the first two of the year — that lasted six innings.

So what’s the problem? Well … how much time ya got?

For the record, I don’t see significant differences in the mechanics, but his average release points has been a bit lower than what’s been typical. This doesn’t explain much, if anything at all.

Let’s start at the beginning with the fastball.

Iwakuma’s four-seamer has never been less valuable to him in a starting role than in his first six starts of 2017, but opponents are hitting the sinker, curveball and cutter, too.

Iwakuma’s splitter and slider remain highly effective in the relatively small sample that is six starts and 173 pitches. But he’s been unable to create ideal situations  for those pitches, and he’s having to work harder than ever to get into those counts, which is shortening his outings.

Iwakuma allowed a .219 average and .387 slugging on four-seam fastballs a year ago. As you can see in the above image, courtesy of brooksbaseball.net, batters have killed Iwakuma’s four-seamer in 2017.

Batters are swinging at first-pitch fastballs more often and putting it in play — often for hits. Without a more effective get-ahead sequence, Iwakuma’s strikeout numbers are going to continue to drop. And drop they have.

 

The above image from FanGraphs shows Iwakuma’s strikeout rate is down more than five percent, while his walk rate is up almost four percent.

This is a formula for disaster.

More baserunners, more balls in play and a similar rate of fly balls is going to absolutely without a doubt equal more home runs, more doubles, more runs allowed and in fewer innings.

To add insult to injury, so to speak, Iwakuma’s velocity dip comes during a season when it should show an increase. Major League Baseball, starting this season, is using the velo reading from out of the pitcher’s hand, rather than at the 50-foot mark.

It’s added velo numbers to most pitchers, including Yovani Gallardo. And it’s not a matter of it being early in the year. Iwakuma was hitting 88-89 mph in April and May last season.

It gets worse, if trends continue, because Iwakuma’s pitches aren’t moving as much as last year, either.

Horizontal Movement:

Vertical Movement:

I’m not suggesting Iwakuma is simply done at 36 years old. I’m not suggesting he’s hurt, either.

The numbers, however, suggest both as possibilities.

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Jason A. Churchill

Publisher, Executive Editor, Director of Analysis Jason founded Prospect Insider in 2006 after getting his start at Inside the Park three years prior. He spent years covering prep, college and pro sports for several news outlets, both local and national, including MLB.com and ESPN Insider. He served as co-host of the afternoon drive show on 1090 The Fan CBS Sports Radio from 2013-2015. He's not done podcasting yet and now serves as managing editor at HEROSports.com.

One thought on “Checking Hisashi Iwakuma

  1. I for one am hoping his vesting option isn’t met. That 10+ million could turn into a pretty nifty upgrade in the rotation.

Thoughts?