Further evolution for Frankie Montas

After landing with the Brewers at the trade deadline, Frankie Montas looked like a different pitcher. Yes, the results were better — 4.35 FIP and 10.99 K/9, compared to a 4.92 FIP and 7.52 K/9. But he literally looked different, likely a testament to improved strength in his surgically-repaired shoulder. 

Frankie Montas  Attributes	Arm Angle	Vertical Release Point	Horizontal Release Point	Avg. Four-Seam Velocity
April 2024	37.5 degrees	5.82 ft.	-1.34 ft.	94 mph
Sept. 2024	47.7 degrees	6.01 ft.	-0.9 ft.	96.1 mph

The Mets apparently liked what they saw, inking Montas to a two-year, $34 million contract earlier this offseason. Under PBO David Stearns, New York has quickly developed a reputation for reviving veteran starting pitchers. What might they have in store for Montas? 

My anticipation starts with his sinker, since the Mets are suddenly at the forefront of the sinker’s quasi-renaissance throughout MLB: Only the Giants (26.4%) and the Phillies (25.7%) threw sinkers more often than New York did last season. Eight of the nine pitchers to start at least five games for the Mets used a sinker. That’s not to say they have a staff full of sinker-ballers. As Mets pitching coach Jeremy Hefner told The Athletic in May, sinkers are simply another tool in a pitcher’s toolbox. 

Hefner also admitted that the Mets have a better understanding of “what a good sinker is,” noting that a strong sinker shape relies on either plus run, or plus depth. We can see the sinker diversity among the group of Mets starting pitchers, past and present, in the table below. 

Mets Sinkers	Pitch%	Horizontal Movement	Vertical Movement	Velocity	Stuff+
Clay Holmes	56.3%	14.5	25.2	96.6	102
Sean Manaea	44.7%	15.9	22.7	92.3	95
David Peterson	31%	14.8	25.7	91.9	102
Jose Quintana	30.4%	13.9	20.6	90.8	76
Luis Severino	24.8%	14.5	18.3	95.6	90
Frankie Montas	19.1%	13.9	21.2	94.8	83
Jose Butto	12.3%	15.4	21.6	92.8	83
Tylor Megill	9.5%	15.6	22.5	94.6	108
Paul Blackburm	6.4%	12.4	22.8	91	69

Sinkers with more vertical movement — more ‘sink’ — seem to grade better on a Stuff+ scale, which feels intuitive: Sinkers are typically designed to sink. But I’d argue that a successful sinker has just as much to do with optimization and arsenal fit. This is where Hefner and the Mets have learned to thrive, and I expect Montas to reap the rewards, following a couple of blueprints. 

Let’s start with Luis Severino, who came to the Mets after hitters clobbered his traditional four-seam/slider pairing during his swan song in the Bronx. In Queens, Severino’s early-season revival was predicated on a sinker, which he used to offset his four-seamer and suppress barrels. Later on, Severino sustained his turnaround by introducing a wicked sweeper, which became a swing-and-miss pitch against both righties and lefties. 

While Severino’s sinker lacked exceptional movement — touting below-average run and drop — it played well with his sweeper, which generates extreme gloveside movement. The two pitches combined to expand the plate horizontally, neutralizing right-handed bats. 

Tylor Megill, on the other hand, introduced three pitches — a sinker, cutter, and splitter — into his arsenal last season, taking the onus off his four-seamer and slider. Megill’s pitch plot looks a bit like a kitchen sink, but there’s a narrative there: He first deployed a sinker in July, becoming a true three-fastball pitcher. Right-handed hitters had clubbed his dead-zone four-seamer (.412 wOBA in 2023), so in September, he became a sinker-oriented pitcher against RHB (.196 wOBA), maximizing the armside run by pitching inside. 

There are kernels here for Montas to follow. 

Frankie Montas's Pitch Plot w/MIL

Last season, by Pitcher Run Value (PRV), the sinker graded out as Montas’s best pitch: It generated weak contact and often found the zone, offsetting poor swing-and-miss totals. The Brewers — more so than the Reds — seemed to recognize its value,and Montas deployed his sinker with higher frequency against both RHB (29.7%) and LHB (20.7%) as an early-count weapon. Milwaukee also toyed with the sinker’s shape, making it less depth-y. 

We can track the long-term evolution of Montas’s sinker through the table below. 

Frankie Montas Sinker Shape, by Team	Armside Run (in.)	Vertical Drop w/gravity (in.)
Athletics	15.4	17.5
Yankees	15.2	18.7
Reds	14.2	22.3
Brewers	13.6	20.1

That’s all fine and good, and I agree with the decision to make his sinker ‘sink’ less. But that change could be maximized with additional horizontal movement. Judging by Hefner’s criteria for a successful sinker, I think that’s a change that the Mets and Montas will aim for in 2025. 

Turns out, there’s a lot of room to grow. To see where Montas’s sinker ranks in terms of horizontal movement, I downloaded a CSV file from Baseball Savant containing data for all right-handed starters who threw a sinker last season. From there, I ran the following SQL query: 

SELECT player_name FROM ‘mytable’ WHERE pitch_percent >= 15.0 ORDER BY api_break_x_arm DESC

Out of 76 right-handed starting pitchers who used a sinker at least 15% of the time, Montas ranked 55th in armside movement (Severino, by comparison, is 51st). That leaves Montas with a couple of choices: He can either add armside movement to his sinker, or gloveside run to his slider, creating more of a sweeper. Maybe he can do both. But he should aim to expand the plate in the same vein that Severino did to continue to neutralize right-handed hitters. 

The benefits of a running sinker are clear against RHBs, whom Montas would look to jam. The equation is a little more complicated against LHBs, which have long been Montas’s Achilles heel. He used to be sinker-heavy against LHB, and it never really worked — the lowest single-season wOBA was .379, back in 2021. 

As mentioned earlier, Milwaukee upped Montas’s sinker usage to lefties. The results were mixed: a .160 xwOBA in August, followed by a .649 xwOBA in September. To achieve a late-career turn-around, Montas needs to find an option against LHB, and I wonder if his new-look sinker would be a viable option. 

To explore this question, I took the league average sinker movement among RHPs, which is 7.3 IVB and 14.8 armside run. Then, I sorted all right-handed sinkers into four buckets, categorizing by drop and run. From there, I extrapolated the platoon splits to generate the following table:

Less Run, Less Drop  RHB — .347 xwOBA  LHB — .369 xwOBA	More Run, Less Drop  RHB — .334 xwOBA  LHB — .366 xwOBA
Less Run, More Drop  RHB — .347 xwOBA  LHB — .377 xwOBA	More Run, More Drop  RHB — .331 xwOBA LHB — .380 xwOBA

Two things stood out. One, sinkers with more run tend to fare better against right-handed hitters, which makes sense, assuming that they’re able to maximize the run by pitching inside. That’s what Montas does well, and should continue to do. Second, sinkers with less drop fare better against left-handed hitters, though the platoon splits are still very much apparent. I don’t have a great reason for this, but off the top of my head, I wonder if it has to do with the atypical movement profile — hitters expect sinkers to sink, and if a sinker drops less, I’d imagine it would catch the hitter somewhat off guard. On the other hand, you could argue that a sinker without sink boasts few redeeming qualities, and should be easier to hit. That seems fair, too. 

Nevertheless, Montas should strive for the top right corner: a sinker with more run and less drop, which would continue to neutralize righties, and at least offer the best chance against lefties. Then, perhaps he can use his sinker in the same vein as Megill, who sprinkles in all three of his fastball offerings to keep LHB on their toes. 

Overall, the key for Montas against LHB is probably his cutter. Of all his pitches, the cutter grades the worst on a PRV scale, thanks to poor batted-ball contact, a mediocre whiff rate, and an inability to throw it for a strike. But fastball-cutter-splitter — with a smattering of sinkers — is probably the best attack plan, especially considering we’ll lean sinker/sweeper (or slider with sweeper-y movement) against RHB. 

A quick note on Montas’s slider, since its modifications will work in conversation with his sinker. The Brewers retooled his slider after the trade deadline: 

Montas SL, CIN: 8.0 in. GLV >> 4.7 in. IVB

Montas SL, MIL: 6.6 in. GLV >> 1.2 in. IVB

Success followed, as Montas’s slider ran a 47% SwStr rate with the Brewers, up from a mere 16% with the Reds. I think the success, though, has more to do with the fact that his modified release points made the slider appear more like the rest of his arsenal out of his hand. On top of that, by limiting its vertical movement, Milwaukee created needed separation between the slider and the cutter. But moving forward, I’d recommend adding more of the gloveside break, as I mentioned earlier — that way, Montas can pound RHB inside with his sinker, and run sliders or sweepers off the outside corner, continuing to generate whiffs.