Some systems are simple and obvious. Put a piece of paper into a shredder and confetti comes out. Put a dirty car through a car wash and it comes out clean . Put a little tray of cake batter into an Easy-Bake Oven and a little cake comes out (or at least, I assume it does. I never had one, even though I always kinda wanted one).
Pitchers, however, are not a a simple and obvious system. A vast array of inputs— pitch type, location, arm angle, grip, and more— go in, and a vast array of outputs—K%, spin, break both horizontal and vertical, so on, so forth— emerge. But the story need not always be complicated. Jesús Luzardo is having the best season of his career, with what would be a career low ERA (3.02) and WHIP (1.12). The output is as good as it’s ever been. So it stands to reason that the input—the pitches he’s throwing— are better than ever before too.
And they are! Only, they’re not. It’s both. Half of them are. Half of them aren’t.
| Pitch Type | wOBA, 2025 | wOBA, 2026 |
|---|---|---|
| 4-Seam Fastball | .345 | .364 |
| Changeup | .278 | .344 |
| Sinker | .455 | .352 |
| Sweeper | .231 | .165 |
If you’d prefer to think in terms of batting average or slugging percentage, those follow the same pattern. Luzardo’s four-seamer and changeup are worse than last year, and his sinker and sweeper are better. This raises two questions: how is he pitching better, when half of his arsenal got worse? And how did his pitches change?
Let’s start with the first, because it’s fairly simple. For one thing, he’s throwing what is now his worst pitch, his four-seamer, less. It was his primary offering until now (technically, it did dip just beneath his now-extinct slider in 2022) He offered it 33.3% of the time in 2025, and 25.9% of the time this season. The spotlight that was once given to his four-seamer has now been given to his sweeper (38.2% usage, up from 33.3%) and sinker (17.3%, up from 10.8). He’s also removed his sparsely-used slider from the equation. Throw what’s working better more, and what’s not less; that’s a simple recipe for improving your overall output even if not every piece is improving. It also helps that the biggest positive change, the improvement in his sweeper, is in one of his primary offerings, and that the biggest negative change, the decline in his changeup, is in one of his secondaries.
So with that out of the way, what’s happened to the pitches themselves? There is one underlying change that affects all of them: his arm angle has dropped from 32 degrees to 29. His velocity has changed for the changeup (nearly two MPH less than last year), but his other three pitches are coming in at the same speed. Spin-wise, three of his pitches look mostly unchanged, but the changeup is moving differently: last season the spin direction was 9:45 on a clock, and this season it’s 9:00. He’s getting a little more vertical drop on all of his pitches, too, particularly on the sinker.
The improved drop may explain the sinker’s improved performance, or at least part of it. But the sweeper isn’t so different from last year, in terms of movement and velocity. By Stuff+ (a model that measures most everything that goes into a pitch except for location), it’s not meaningfully different from last year. How is he getting better results with it? He’s using it differently, for one thing. He’s dramatically increased his usage of it as a tool to push an advantage over batters, using it 54.3% of the time when he’s ahead in the count (from 37.8% last season), and about half the time when he’s got two strikes on a batter (from 34.1%).
But how about his control? By Location+, (which measures how well the pitcher locates a pitch, but doesn’t take velocity, movement, etc. into account), he’s actually worse at placing it than last year. And by Pitching+, which takes everything into account, the pitch is simply worse than last year (though still above average). Unfortunately, the data for this gets a bit messy: it combines sliders and sweepers, and last year Luzardo was still throwing his slider 6.5% of the time. So he may not actually be worse, or at least, not as much worse as it seems, at locating the sweeper this year. Perhaps he was particularly good at locating the slider, and removing it from his arsenal simply made it look like his control of the remaining sweeper got worse. But as I don’t have the ability to remove the sliders from the 2025 data, that’s just conjecture. It’s just strange that he’s getting such better results with a pitch that might, by some models, be worse.
Some systems are complicated. Luzardo’s sweeper is one of those. It’s not immediately clear to me how he’s getting improved results with it this year. Maybe the arm angle has done something to it that makes it harder for batters to pick up on. Maybe a change in one of his other pitches has had some sort of domino effect. Maybe it’s the changes in how often and in when he’s using it. Maybe pure variance is having an effect. Maybe it’s something finer, something that you’d need a proper pitching guru to see.
I’d really like to know. But I’m also not complaining.
COVERS INTEL: Nola has been leaning hard on his knuckle curve as he turns around his season, throwing it 33% of the time, nearly 10 percentage points more often than his four-seamer. 
Kyle Harrison 
Spencer Arrighetti 
Elly De La Cruz
