Three Pittsburgh Pirates pitchers who have made changes

Hunter Stratton

The Pirates originally drafted Hunter Stratton in the 16th round of the 2017 draft out of Walters State Community College. Stratton did not impress as a starting pitcher through his first few pro seasons but transitioned to the bullpen full-time in 2021 and has steadily improved each and every season. After a strong second half last year with Triple-A Indianapolis, Stratton made his Major League debut, pitching a dozen innings, only allowing three earned runs with ten K's and three walks.

Despite the strong debut, the Pirates still opted to non-tender the late-blooming relief prospect that off-season. The two sides re-upped on another minor league deal a month later, however, and the move has looked great for the Pirates so far. In 16 innings, Stratton has a quality 2.76 ERA, 3.03 FIP, and 0.92 WHIP. He's struck out 18 batters while allowing two home runs. But the most impressive part is how good he's been at limiting walks. He's handed out just a single free pass and has been able to handle higher-leverage situations without much trouble. Stratton has the 3rd highest winning probability added among Bucco bullpen arms.

Stratton has a three-pitch mix. There's his four-seam fastball that sits mid-90s and has been highly effective. Batters have a .180 wOBA against the pitch with a whiff rate of 29.5%. When they do make contact, they've only been able to muster an exit velocity of just 86 MPH. Stratton's slider has been even more effective, with a .149 wOBA and 56.5% whiff rate. 

But Stratton utilizes a third pitch, and that's a cutter. This pitch is his primary offering as he uses it 42.7% of the time. While it hasn't been nearly as effective as his four-seamer or slider, as opponents have been able to hit the pitch for a .380 wOBA, batters are still swinging and missing at the pitch 27.8% of the time, which ranks top 30 among all pitchers who have thrown cutters in at least 10 plate appearances.

The two pitches Stratton has changed up are his cutter and four-seamer. Last season, his cutter only sat 90.7 MPH. It didn't have great vertical movement at 26.1 inches, but it moved 5.9 inches horizontally, which was the 6th most among pitchers who threw a cutter at least 50 times. So far this year, he's taken a different approach with his cutter. Stratton is now throwing the breaking pitch harder, sitting at 92.1 MPH. However, this means he has sacrificed some movement. His cutter has 21.5 inches of vertical drop and 2.7 inches of horizontal break. 

His four-seamer, on the other hand, has gained more movement. While Stratton didn't lose much velo off his fastball, he did add some ride to it. In terms of vertical drop, his fastball has gone from 16.3 inches to 13.9 inches. On top of that, he's seen his four-seamer's horizontal break go from 0.9 inches to 2.1 inches. He's added about 6% of active spin to his fastball, giving it better movement.

Stratton has been really good so far, and his stuff has looked great in the early stages of the 2024 season. He's definitely worked himself into a potential high-leverage role. For a late-round draft pick who went to a community college, was non-tendered, and resigned to a minor league deal, Stratton could end up being one of the Pirates' best bullpen anchors moving forward.

Kyle Nicolas

Kyle Nicolas was a former second-round pick by the Miami Marlins who was traded to the Pirates for Jacob Stallings. A hard-throwing right-hander throughout the minor leagues, Nicolas had a strong second half to 2023 and made his debut that year. While his debut wasn't great, he pieced together a solid final few weeks of the year. Nicolas opened 2024 at Triple-A after an unimpressive Spring Training but is back in action in the big leagues and looks better than ever before.

Nicolas has only pitched three innings so far, but he already has five Ks. While he's walked two batters, he's allowed just an 86.8 MPH exit velocity in the microscopic sample size. Batters have a whiff rate of 36.8% against his stuff and a chase rate of 30.8%. Both are well above average, with the former being in elite territory. For reference, Spencer Strider was in the 98th percentile of whiff percentage at 38.6%.

The young reliever has his elite fastball to thank for that. He's throwing harder than ever, averaging out at 98.2 MPH, an uptick from 96.8 MPH last year. The fastball plays way up for a few reasons. The first is the ride through the strike zone. His four-seamer only has 10.5 inches of drop with nearly as much horizontal break. Nicolas releases the ball nearly seven feet in front of the rubber. This adds an extra tick of velocity to his already powerful fastball. What might be a 98 MPH fastball on the radar might look like 99-100 MPH out of the hand.

Nicolas's primary breaking pitch is his slider. He throws it very hard, averaging 91.5 MPH, which would tie him with Mike Baumann and Mackenzie Gore for the hardest-thrown sliders in baseball right now. However, the pitch has a well above-average horizontal break at 4.5 inches and 29 inches of drop.

Nicolas has gained some movement on his fastball, but the pitch he's truly reworked is his curveball. Like the rest of his pitches, it has gained velocity. He went from throwing it 83.8 MPH last year to 85.7 MPH this year. The vertical movement hasn't changed much at 49.8 inches compared to 50.1 inches last year, but he's throwing it with much more horizontal break. He's now averaging 9.3 inches of break compared to just 3.7 inches last season. Nicolas' curveball has gained nearly 300 RPM, going from 2400 to just shy of 2700 this year.

Nicolas' curveball was definitely his worst pitch heading into this year. It had worse movement compared to his fastball and slider. But if it's truly a third above-average pitch, it could make him an elite relief pitcher for the Pirates. His fastball is easily a plus-plus pitch, if not an elite offering, while his slider is a plus pitch. Now, if his curveball is a reliable third offering, he could be a lockdown arm in the future.

Josh Fleming

Even if you're not a fan of Ben Cherington's work, one thing you have to admit is his ability to find soft-tossing lefty pitchers and make him effective arms for the Pirates. They've been able to do that with a few arms this year, one being Josh Fleming. The Pirates signed Fleming to a split deal, and his numbers heading into this year weren't all that impressive. He had spent the four prior seasons with the Tampa Bay Rays, owning a 4.88 ERA, 4.63 FIP, and 1.42 WHIP in 223.1 innings working as an up-and-down swing man arm.

But Fleming is off to an outstanding start to the 2024 season. He's pitched 16 innings while only allowing two earned runs. He only has a 15.9% strikeout rate and a 9.5% walk rate, but the southpaw excels at limiting hard contact. He is in the 90th percentile or greater in exit velocity (84.2 MPH), barrel rate (2.2%), and hard-hit rate (28.3%). Plus, he has a ground ball rate of over 60% at 63%.

Fleming has a four-pitch mix, including a fastball that sits 90-92 MPH, a low-80s change-up, as well as an upper-80s cutter. Fleming will also occasionally mix in a curveball from time to time. But how did this lefty who had a meager 83 ERA+ for the Tampa Bay Rays and couldn't make much progress under their notorious development staff all of a sudden become a quality left-handed reliever for the Pittsburgh Pirates?

Well, part of it has to do with his curveball. He's barely used the pitch, only throwing it five times. This is an offering he used 10.9% of the time in 2022 and 22.1% of the time in 2023. In neither year did it produce overly impressive numbers. But the big change has been his cutter.

The cutter was the second most-used pitch in Fleming's arsenal in 2020 and 2021 and his third most-used pitch in 2022. But he didn't throw a single one in 2023. Now, he's using it 25.9% of the time. But bringing back the cutter is only half of the story.

Like Stratton, Fleming is throwing his cutter harder than in previous seasons. In '22, he sat 84.3 MPH with the pitch. Now it's up to 87 MPH. While the amount of spin hasn't drastically changed, how he spins it has. His cutter's active spin rate went from 32% in '22 to 53% in '24. He has sacrificed some vertical break, going from 32.5 inches to 28.5 inches, for horizontal movement, rising from 0.8 inches to 2.5 inches. So far, batters have a .227 wOBA against Fleming's new and improved cutter compared to over .400 two years ago. Batters also seem to be very fooled by his stuff, and not just his cutter, as he has a 37.4% chase rate.

Fleming has been a great addition to the Pirates' bullpen. 

They needed a good long-reliever and it looks like they may have found it. So far, he's pitched two or more innings on three different occasions. For someone they picked up with little fanfare, this could be their Ryan Borucki 2.0 signing.