Mound Visit: Secondary pitches could be key to Jones maximizing potential

From emerging as a sudden candidate to earn an opening day roster spot to solidifying his role as an important piece of the Pirates’ starting rotation, Jared Jones has reasons to look back on his rookie season with a certain level of pride and confidence. 

At the age of 22, Jones showed that both his pitching ability and his stuff -- primarily his four-seam fastball and slider -- play at the highest level. His skill as a pitcher, coupled with his ability to make the most of his fastball-slider-centric pitch mix, translated to stellar overall production in the form of a 6-8 record, a 4.14 ERA and a 1.19 WHIP in 22 starts in a big-league uniform. 

His immediate success, which began with a 10-start sample in which he posted a 3.05 ERA with 68 strikeouts and 10 walks over 59 innings, was certainly worthy of praise. But there was a bit more to be desired on Jones' part, primarily due to the late season struggles he endured in posting a 5.17 ERA over a final 12-start stretch that followed a nearly two-month stint on the injured list. 

"Just being myself, I would say it was terrible," Jones said, reflecting on his season following his final start against the Yankees in the Bronx on Sept. 27. "A lot of other people would say I had a pretty good one. After injury, I kinda let some things go a little bit. Didn't have some of my best starts. Everything just kinda went up on me. That type of stuff happens during a long season, which is OK. There is a lot of room for improvement." 

I'm sure the right lat strain that caused Jones to land on the injured list in early July didn't help his cause, but perhaps he became a bit more predictable as the season went on. The more he faced guys multiple times throughout the year, the more they were able to study his tendencies and see how much he relied on his fastball, which he turned to 49% of the time, and the slider that saw a 35% usage. 

As he prepares for his second major-league season, it's possible that Jones' further improvement might begin with implementing more of the secondary pitches -- curveball and changeup -- that he showed glimpses of throughout a 2024 season in which he ultimately struck out 132 batters and walked 39 over a total span of 121 1/3 innings. That's not to say the heavy doses of four-seam fastballs and sliders weren't enough for him to hold his own against major-league hitters, but a level of unpredictability could be gained by mixing more of his other weapons in there. 

First, let's take a look at those primary pitches that Jones thrived with. He used his four-seam to overpower hitters with an average velocity of 97.3 mph, ranking in the 93rd percentile in fastball velocity and in the 72nd percentile in fastball run value (6), according to Baseball Savant. He limited opposing hitters to a .224 batting average and seemed to reach triple digits with relative ease at times. Here he is hitting 100 in his final start of the season against the Yankees, an encouraging sign considering he had just come off a start in Cincinnati in which he experienced a dip in velo: 

Jones’ slider served as a reliable complementary piece and, like he did with his fastball, he struck out 59 batters with the breaking pitch while holding opposing hitters to a .208 average. Not exactly a surprise considering he’s capable of making good hitters like Milwaukee’s Brice Turang look silly with a slider that comes in on a guy at around 90 mph:

When Jones struggled down the stretch, there were times when he didn’t feel good about the results he was getting with various weapons, including his slider, a pitch he admittedly "lost confidence" with during a start against the Cubs on May 10. In those instances when his secondary stuff wasn't working and he wasn't able to land an offspeed pitch, Jones was left vulnerable with only his fastball at his disposal. As good as his fastball was, opposing hitters knew he relied on that and his slider more than any other pitches and were ready for them. It goes back to that predictability factor associated with those two frequently-used pitches. 

While they have certainly served their purpose as weapons within Jones’ arsenal, he did mix in a 9% usage of a curveball and a 6.6% usage of a changeup, two pitches that could be crucial to a successful future as a major-league starter and allow him to maximize his potential on the mound. But he has to be able to throw them effectively and with confidence to keep hitters off-balance. 

Jones found mixed results when turning to those third and fourth pitches this season, as opposing hitters batted .348 against the curve and .317 against the changeup. The hard hit rates against Jones were pretty noticeable all the way around, too. He ranked in the 8th percentile with an average hard hit rate of 44.5% -- changeup (48.5%), curveball (47.1%), fastball (46.5%) and slider (40.3%) -- meaning hitters were producing batted balls of 95 mph or more at a pretty high rate. 

It wasn't all bad, though. Jones was able to post a 32.7% whiff rate with his curveball and generated a putaway percentage -- the rate of two-strike pitches that result in a strikeout -- of 25% with his changeup. That’s slightly higher than his 24.9% rate with his slider and 24% rate with his curveball. 

Jones knows that further improving those secondary pitches and implementing them more can only create better opportunities in terms of pitch sequence. We’ve seen how productive guys like Paul Skenes and Mitch Keller have been with extensive arsenals. When one or two pitches aren't working for them, they can remain effective with other weapons to turn to, and they're confident in doing so. For Jones to take another step forward as a reliable top-of-the-rotation starter in year No. 2, it might be wise for him to gain enough comfortability with the curveball and changeup that he can confidently turn to them more often as additional weapons in 2025. 

“Finding the curveball in the back half of this year, it's going to be good for next year,” Jones said. “I felt like against some teams, I went fastball-slider and just sprinkled in a really bad curveball and really bad changeup. Getting some fine details down on those other two pitches will be better for next year."