MLB Pipeline Pitching Lab: Jonah Tong

Jonah Tong recalls school nights back home in Ontario when he’d stay up until midnight throwing with his father, Alex. The sessions would go so late that his mother would yell across the street for both to come inside. The paternal instruction was a little different.

“My dad always told me, ‘Don’t go sidearm,’” he said. “So I think it was one of those things where I just [wanted to] see if I can throw overhand and see if he says anything. He didn’t really say anything because he was just coming off of work. After that point, I was messing around for so long that it started slowly ticking up.”

The result was an over-the-top delivery that, all these years later, is taking the lower levels of the Minor Leagues by storm and a little reminiscent of another undersized hurler.

“Someone I tried to look to for mechanics was Tim Lincecum,” Tong said. “I get that comp a lot.”

Ranked as the Mets’ No. 20 prospect, the 6-foot-1 right-hander has enjoyed a storybook rise to prominence – from Canada to the Georgia Premier Academy to the MLB Draft League to the seventh round of the 2022 Draft, where he signed for full slot at $226,000.

After being limited to 21 innings last season, Tong stormed out of the gate with four scoreless appearances for Single-A St. Lucie this spring. He struck out 36 batters and held them to a .115 average through 18 2/3 innings. Tong, who turned 21 on Wednesday, was quickly promoted to High-A Brooklyn where he’s been more challenged (4.26 ERA in eight starts), but his 34.7 percent strikeout rate between the two levels is tops among Mets Minor Leaguers (min. 50 IP) and seventh among the 338 Minor Leaguers who meet that frames standard.

The New York hurler spoke to MLB.com about the four-pitch arsenal that has made him such a force in 2024 and could have him impacting the Major League rotation down the line.

FASTBALL

Much of the dominance comes down to Tong’s four-seamer, a pitch he threw 60.1 percent of the time during his run in the Florida State League. There isn’t much special about the righty’s grip on the heater – it’s a standard four-seam look – and the pitch averaged 92.8 mph at Single-A, though it touched as high as 97.2.

But what makes the pitch so special is its significant carry.

Tong’s fastball averaged 20.6 inches of induced vertical break in the FSL, the highest average IVB in that circuit among pitchers with at least 100 four-seamers thrown in 2024, and was released with above-average extension of 6.6 feet. Batters whiffed on 48.1 percent of their swings against Tong’s fastball, again the top mark in the category for the league. Consider that the Major League four-seam whiff leader (again, minimum 100 four-seamers thrown) is A’s rookie Mason Miller at 41.9 percent. Miller’s triple-digit fireballer is a different offering than Tong’s effective riser, but that illustrates just how dominant the latter truly was at Single-A.

In layman’s terms, batters begin to swing, thinking they’re getting a low-90s fastball in the zone only to hack under a pitch that comes in closer to the letters. Because of the high release and extension – there’s that Lincecum comp again – they might have a tough time and little time to pick up on the pitch to begin with.

Tong credits his over-the-top delivery with creating the IVB necessary to get so many misses at the top of the zone. That trait in particular was one the Mets picked up on during the righty’s run through the Georgia Premier Academy, and once the organization got him in the fold, they wanted to emphasize what they saw as his greatest strength.

“During my first bullpen session, we noticed that I did have a lot of carry in my fastball,” Tong said. “That led us in the direction of going, ‘OK, when you’re pitching, you’re typically really effective up in the zone. So that’s been a big focus for me this year.”

CURVEBALL

While Tong threw his heater three-fifths of the time in the FSL, he needs more than that to keep hitters from sitting fastball, especially as he climbs the ladder toward Queens.

Enter his mid-70s curveball, which gives him the south portion of his north-south approach. The deuce averaged 67.4 inches of drop in the FSL. Once again, that’s the most downward movement (including gravity) of any curve thrown at least 25 times in that league. Batters swung 10 times against the 12-to-6 option and missed five times for a clean 50 percent whiff rate.

In other words, if they’re thinking high, they struggle to make contact when the curve drops low. If they’re only sitting fastball, Tong is also capable of plopping in a breaker at the bottom reaches of the zone. Even the threat of the curveball can be as effective as the pitch itself.

“[I use it to] play off my high fastball, and I may use it to get ahead in counts,” he said. “Then later in the count, I may use it as a tunneling pitch off my fastball up in the zone.”

And if you’re around for a Brooklyn start this summer, keep an eye out for Tong’s curveball usage in his pregame routine.

“Ironically, it’s the first pitch in the bullpen prior to the game,” he said. “As soon as I throw it, it’s an a-ha moment where I know it’s going to have a good day.”

SLIDER

Working up and down has certainly been effective for Tong, but adding a horizontal option has been important as part of Tong’s development over the past year. It averaged 86.4 mph in the FSL, putting it nicely between the fastball and curve from a velo standpoint. With 5.7 inches of gloveside movement, it isn’t a huge sweeper, but it’s not exactly a short cutter either.

“I categorize it as a slider,” Tong said. “I know metrically, it can feel more like a cutter than a standard slider or a hard slider, whatever your choice. It’s been one of those pitches that bridge my fastball and curveball, seeing as they are pretty big for their shapes.”

Tong actually threw the slider more than the curveball with St. Lucie, in part to focus on its in-game development, and 36 of his 43 sliders were thrown to fellow righties. The sharp break is just enough to befuddle hitters who are looking for the louder options.

“Just a high-zone pitch for me, especially one that in theory should give me a ton of called strike-whiffs,” Tong said. “That will help me get deeper into counts and deeper into games because I have something else to go to instead of the two big shapes.”

CHANGEUP

Tong and his dad picked up curveball grip from the Internet, and he went back to the well for his current changeup, picking up a Vulcan-style grip from the Instagram feed of former Minor League right-hander Robby Rowland. It’s a fun grip for the right-hander who used to put rubber bands around his fingers to mimic the Star Trek hand gesture.

Averaging 85.0 mph, Tong’s changeup comes in around the same velocity as the slider but moves the other way with nine inches of armside run. As is the case with most right-handers, the Mets prospect saves the cambio primarily for lefties, throwing only one to a same-sider hitter during his time with St. Lucie. But it’s tough to argue with the approach, given that lefties have hit just .159 with 32 strikeouts in 97 plate appearances against Tong between Single-A and High-A this season.

“For now, we’ll have to wait and see,” Tong said. “It’s been really effective against lefties. Righties, I typically go more to my slider because it tends to miss bats.”