Sergio Romo Isn’t Entirely Not Greg Maddux

It might be hard to believe this after Sergio Romo closed out the World Series and probably wrapped up the stopper role going forward for the Giants and Team Mexico, but there was a time when the prognosis for his career was much more negative. After all, he’s a small righty (five-foot-ten and a buck-eighty-five) with a fastball that doesn’t normally crack 90 miles per hour who throws his slider more than half of the time. Given what we might know about injuries and platoon splits, there was probably one role waiting for him in the bigs: ROOGY.

But Sergio Romo is not a Righty One-Out GuY. I asked him why.

“It’s all about having confidence in my stuff and my abilities,” said Romo when I asked him about platoon splits and his approach against lefties. At first blush, that seems like an evasion. We know that sliders have one of the worst platoon splits of any pitch, and so it’s unlikely that the reliever would continue to throw the pitch more than half of the time against lefties. And he doesn’t:

He’s only faced 306 lefties, but that’s over a third of the batters he’s seen. So, though there were some high-profile moments where Romo was sharing his closing duty with a lefty, he’s seen just about the league average of lefties. And he’s held them to a .237 wOBA, which is better than the .241 wOBA he’s allowed to righties.

But ‘trusting his stuff’ doesn’t mean constantly throwing sliders because they are his best pitch. In fact, it means trusting a pitch that you don’t see much of — his changeup — a little more. It means ditching half his sliders for sinkers. And it means that calling him a fastball/slider guy isn’t quite right. “I’m a sinker-slider type guy,” Romo says, “and I’m more of a control guy.”

Watch where he puts his sinkers against lefties:

Just as he uses the slider on the outside corner against righties, Romo uses his sinker on the outside corner against lefties. I asked him to talk about that fastball that allows him to evade platoon splits despite mediocre velocity.

“My fastball? Don’t sleep on it!” he said with a smile. “I feel like I got a sneaky fast fastball — I don’t throw 95, so I don’t try to throw 95.” He added that he just tries to keep the ball down in the zone, an adage that fits the heatmaps.

But it is interesting to hear him talk about one name, and it might be the name that helps Romo stand out from the list of Relievers Without a Fastball. “I used to idolize Greg Maddux when I was younger, those were the days that he didn’t throw 94, 95, 96.” It’d be fun if Sergio Romo had something in common with the patron saint of iffy-velocitied fastballs, wouldn’t it?

It might not seem so at first, but maybe there is a similarity. We don’t have a ton of PITCHf/x data on Greg Maddux, and it is late career, but his fastball averaged -8.7 inches of movement horizontally and 5.8 inches vertically. Romo’s clocks in a -7.5 and 6.6 inches, respectively. But there’s another way to look at this: among qualified righty relievers last season, Romo’s horizontal movement on his fastball was 11th-most. His sinker has even more horizontal movement — 10.5 inches, and fifth-most in baseball over the last three years. And they both have career walk rates around five percent!

Sergio Romo doesn’t have to be Greg Maddux to not be a ROOGY. His fastball doesn’t have to be as good as a first-ballot Hall of Famer. But that fastball and sinker do have elite horizontal movement, and they do break in the opposite direction of his slider. That movement, plus his great control, have helped Romo avoid getting pigeonholed as a guy who couldn’t get lefties out. Don’t sleep on that fastball, indeed.