Koji Uehara’s Fastball Use, Command Is Major Key To Closer’s Success

It wasn’t yet time to go into full panic mode about Koji Uehara, but things certainly appeared to be heading in that direction.

The Boston Red Sox closer looked downright bad over the weekend in Baltimore. He allowed two runs on four hits in 1 1/3 innings of work, including a blown save and a loss Saturday night. Even on Friday night in a save against the Orioles, there were moments where Uehara looked like he was throwing batting practice.

One reason for his struggles seemed to be an apparent over-reliance on the split-fingered fastball. The splitter is Uehara’s best pitch, but without an effective fastball, the splitter becomes much more hittable. Good hitters won’t swing at low splitters knowing the pitch will dart out of the strike zone. The bad splits, like the one to David Lough on Saturday night (see the location below), those usually get hit a long way.

It’s vital for a pitcher who makes a living on the splitter to at least have something of a fastball to keep hitters honest. On Friday night against the Orioles, however, 19 of Uehara’s 21 pitches were splitters. He eventually got out of the inning relatively unscathed, but he was hit some and had struggles getting the O’s to chase as the inning went on. Also, it’s unclear why — maybe he just felt a little off — but Uehara’s velocity was down over the weekend. Those two fastballs registered at just 86 mph, which may explain the apprehension to throw No. 1.

Then on Saturday night, things got worse. He threw 14 pitches in that outing, increasing his fastball usage to five. However, Uehara’s velocity dropped even more, with those five fastballs averaging 85.2 mph.

It was admittedly a small sample size, sure, but every large sample size starts with a small one. When you’re talking about 40-year-old pitcher who’s had recent injury issues, velocity is going to be the first thing you look at when dissecting problems, especially when the pitcher’s secondary offerings — like Uehara’s splitter — are so dependent on having a believable fastball.

However, those concerns have been quelled for the time being with Uehara’s most recent outings. He ended up getting the win in Monday’s walk-off win over the Toronto Blue Jays after working a perfect ninth inning. Uehara threw 16 pitches, and only four were fastballs. However, the fastball velocity saw a noticeable uptick, with an average velocity of 87.25 mph per pitch. That 2 mph jump is nothing if you’re cruising down the Pike, but that makes a difference when you’re trying to swing a piece of wood at a small ball.

We finally saw the full rebound Wednesday night. The plan seemed fairly evident, as it was clear Uehara and Red Sox catcher Ryan Hanigan wanted to establish the fastball, and boy did they ever. Uehara threw 17 pitches Wednesday against Toronto — nine fastballs, eight splitters. The balance alone was encouraging, but so, too, was the command of the fastball. Not only was Uehara averaging 87.33 mph on his fastball, he was showing an ability to locate.

Fastball location is always important, but for Uehara it makes him that much better. When he’s able to stretch the strike zone by putting fastballs on the corners, it gives him at least another 6 inches to work with. That’s because he knows hitters have to respect that fastball on the outside corner, so by establishing that, he can get hitters to chase the splitter because they have to be able to protect the fastball on the black.

Again, this is all dealing with a small sample size, but Uehara’s performance over his last four outings present at least an interesting study in how important the fastball can be, especially for a pitcher in his role with his stuff.

Thumbnail photo via Bob DeChiara/USA TODAY Sports Images