This story was excerpted from Alex Stumpf’s Pirates Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

ATLANTA – As Luis Ortiz dug in to face Elly De La Cruz in the sixth inning Wednesday at Great American Ball Park, he figured it was time to give the Reds’ slugger something new. Up to that point, he had attacked him with fastballs inside, but with two strikes, he was going to the other part of the plate. If he could locate his four-seamer outside, he could end the at-bat right there. If he missed the spot, well, it could get ugly.

Ortiz delivered a perfect dot to catcher Jason Delay and De La Cruz swung through the high and away offering. Strike three. Ortiz took a brief stroll around the mound, proud of that pitch, proud of his day. Six innings, one run, a career-high-tying seven strikeouts and a win.

This is the guy Pirate fans wanted to see last season. It was fastball velocity that helped Ortiz emerge as one of the Pirates’ top pitching prospects in 2022, but it was the fastball that held him back from delivering on his promise in 2023.

Ortiz has lightning in his right arm, averaging over 95 mph on his fastball, which would normally translate to whiffs and strikeouts with the four-seamer for most pitchers. Instead, it was one of the worst pitches on the staff last season. Batters hit .383 with a .704 slugging percentage against it with a 15.6% whiff rate.

This year, the four-seamer has done a complete 180. Batters are hitting just .238. The slugging percentage against has nearly been cut in half (.357), and the whiff rate has nearly doubled (28.2%).

This isn’t the fastball we saw in 2023, quite literally. Delay caught Ortiz’s Major League debut in 2022 and his first start of 2024, and he knows that his four-seamer is moving differently.

"I think it's less location and more it's true,” said Delay. “He stays behind it and the spin efficiency [and] is not getting the side of the ball or anything like that, so it has more life to it."

When Ortiz was a rookie in 2022, his four-seamer was getting 13.3 inches of horizontal movement. That might sound good, but four-seamers generally do better up in the zone when they have the illusion of rise. Cutting movement kills that illusion, so vertical movement is definitely better than horizontal in this case. This year, his four-seamer is down to 10.6 inches of run, while he’s getting more vertical movement (17.7 inches) compared to last year (16.3).

“It’s been hard work making sure that four-seamer has the spin I want it to have, that movement I want,” Ortiz said, via interpreter and coach Stephen Morales. “It’s been work I’ve been doing the last couple years, and I think it’s in a good spot right now.”

A lot of that work centers around a softball and a product called Clean Fuego, which cuts off the edges of a ball to make it look more like a hockey puck. The outside parts of the ball are colored, and if you don’t see that color when you throw it, it means you’re maximizing spin efficiency. The softball is a tool in his throwing program before he pitches to help prepare his arm, while also helping him better monitor what the rotation of his spin is.

Ortiz will go to those two different balls in his throwing programs when he needs to get the four-seamer on track, but he hasn’t needed to do that much of late. That tends to happen when you record a 3.23 ERA and are making a case to return to the rotation more permanently. Maintaining that fastball success would certainly help his case, even if he says he is fine being used in any role.

“There’s a big difference between how I use my two fastballs,” Ortiz said. “I have the luxury now where I can throw my two-seam inside and throw my four-seam up and away. It’s for sure different how I use my fastball and the spots I use my fastball.”