Three Pittsburgh Pirates pitchers who have made changes

The Pirates have had some of their pitchers succeed after making some changes to their pitch arsenal.
Sep 29, 2023; Pittsburgh, Pennsylvania, USA;  Pittsburgh Pirates starting pitcher Hunter Stratton
Sep 29, 2023; Pittsburgh, Pennsylvania, USA; Pittsburgh Pirates starting pitcher Hunter Stratton / Charles LeClaire-USA TODAY Sports
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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.