TJ Stuff: Opening Day Delights

MacKenzie Gore, Carlos Rodón, Freddy Peralta

Happy Opening Day!

Welcome to “TJ Stuff”, a series which aims to highlight any intriguing MLB players and performances. This article will cover 3 pitchers and their performances on Opening Day.

MacKenzie Gore

MacKenzie Gore was ridiculous yesterday! He racked up 13 K in 6.0 IP as he completely stumped Phillies batters. He allowed just 1 hit, a blazing 112.5 MPH single to Kyle Schwarber, but other than that he was perfect.

Digging deeper into his arsenal, we see that not much has changed with his pitch shapes compared to 2024. His fastball is still sitting 95-97 with upwards of 18” of ride while he secondaries all graded out similarly well. The biggest change Gore made was to his usage. Last season, Gore relied on a curveball and cutter combo as his breaking balls of choice to handle LHH with his changeup used exclusively to RHH. There was one pitch that he seldomly threw which returned excellent results in 2024: his slider.

Gore threw 38 sliders last season, with all but one coming against LHH. The pitch returned a grotesque 52.6 Whiff% and allowed minimal damage. After just a 4.9% usage last season vs LHH, he cranked that up to 51.1 % against the LHH heavy Phillies, and the results were magnificent

On the 23 sliders he threw yesterday, they had the following:

• All 23 were thrown vs LHH (23 of 45 pitches)

• 80.0 Whiff% (10 Swings)

• 0.000 xwOBACON (1 BBE)

It is safe to say that his slider completely shut down Philadelphia’s lefties.

Gore will likely face significantly fewer LHH compared to RHH this season, but when he does, it looks like he has a weapon to counter them. His slider’s subtle glove-side movement helps it run away from lefties and Gore has a tendency to locate the pitch low and away.

You couldn’t have asked for a better start to the season, and Gore did against a juggernaut!

Carlos Rodón

Carlos Rodón followed in MacKenzie Gore’s footsteps as his most noticeable changes came in the form of his pitch usage.

Last season, Rodón tossed his fastball ~50% of the time. While the pitch graded out well in models, he struggled to limit damage on the offering. Batters were able to see his fastball and hit it with authority when given the chance. This approach seemed peculiar because Rodón wields a wide array of secondaries which are all effective at generating whiffs. The most notable of these pitches being his changeup.

As a lefty starter, having a formidable changeup is important. It provides you a tool to attack RHH and can typically be used to put away batters. With its gaudy 49.0 Whiff% last season vs RHH, Rodón only threw his changeup 15.6% of the time while his 4-Seam (49.5 Usage%) allowed a loud 0.441 xwOBACON while returning a below average Whiff%.

Yesterday seemed different. Not only did Rodón slash his overall 4-Seam usage to 25.8%, it was his 2nd most used offering after his slider, and 3rd most vs RHH. It was his changeup that led the way against righties as he tossed 17 (30.4%) while returning an elite 53.3 Chase% and 0.107 xwOBACON.

Another important change Rodón made was the introduction of a sinker into his arsenal. As Rodón has struggled with HR throughout his time in New York, a sinker should help limit damage by LHH. In the small sample yesterday, the pitch was rather erratic, but it was encouraging to see him keep it on the inner third of the plate.

Rodón exhibited exceptional command of his changeup last season, but he never leaned on it as a primary pitch against RHH. His showing yesterday gave us a glimpse of how impactful the offering could be if he optimized its usage. Rodón still has impressive talent, and a usage change may be the key to unlocking his production.

Freddy Peralta

Freddy Peralta made a few large changes yesterday as he struck out 8 Yankees across 5.0 Innings in his 2025 debut. The most notable being the seeming disposal of his slider and improved velocity on his changeup.

Peralta has always been a 4-pitch guy with his primary secondary being his slider. Yesterday we saw a completely different version of Peralta who didn’t throw his slider at all. On a Run Value basis, it was his least valuable pitch in 2024, returning -3 RV while the rest of his average was above average. One noticeable concern with the offering was it extremely wide movement profile; Peralta struggled with its consistency. To start off 2025, Peralta simply did not throw the pitch, and the results spoke for themselves. Whether the removal of his slider is a long-term decision (or even a good one) is still up for debate, but it does simplify his approach with the pitches he has the best feel for.

Peralta’s changeup was another highlight from yesterday as it averaged +2 MPH compared to 2024. This bumped its velocity from the high 80s to the low 90s while also maintaining its shape. The pitch’s combination of run and velocity paired with its separation from his fastball makes its an effective put away offering. It is intersecting to note that his fastball did not exhibit the same velocity increase, but it was ~1 MPH harder than last season.

Peralta has dealt with inconsistencies in recent seasons and he started 2025 off with a massive change in usage. Removing his least effective pitch sounds like the simplest approach to cleaning up his arsenal, and it may just be the correct move!

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