After 16 seasons and 470 career saves, less than 10 away from passing Lee Smith for third on the all-time MLB leaderboard, Kenley Jansen is still looking for every last edge he can squeeze out of the game.
That's why, for example, you'll see him intentionally balk runners to third base to try to stop them from stealing signs -- it's an out-of-the-box way to gain a tiny advantage that might make the difference in closing out a win.
And it's why, even though he has one of the best single pitches of his generation, his cutter -- a cutter so great he can throw it more than eight out every 10 pitches and still succeed -- the pitch he's been tinkering with is his slider … a pitch he throws fewer than once out of every 10 pitches.
But that's what makes Jansen one of the great closers in MLB history, a potential Hall of Famer who's still saving over 20 games a year at age 37.
"With me, I'm just trying to figure out something that can play off the cutter -- to protect the cutter," Jansen said. "That's how I see it."
It's not like the cutter needs much protection. Jansen is approaching 15,000 pitches over the course of his MLB career, and close to 12,000 of them have been cutters. He has collected 945 strikeouts on cutters alone, the most cutter K's of any pitcher since pitch tracking began in 2008 (Madison Bumgarner is next with 752), and the most K's by any relief pitcher on any one pitch type (Craig Kimbrel's fastball is next with 738). Opposing hitters have batted just .188 against Jansen's cutter over nearly 3,000 plate appearances decided by it.
But with Jansen on the verge of passing Smith, and with 500 saves within reach -- a milestone only Mariano Rivera and Trevor Hoffman have achieved -- he's doing everything he can to make his signature pitch as effective as possible for as long as possible.
And that means figuring out the best version of his slider to mix with the cutter, even if he's only going to sprinkle it in.
"It's my cutter first. That's my bread and butter. That's my pitch," Jansen said. "Everybody knows it's coming; I'm going to keep throwing it. So sometimes, when I feel like guys are really on the cutter, I've got to activate my slider. Just make them see something different."
The problem is finding the right slider. Jansen has cycled through a bunch of different versions throughout his career.
Most recently, that search took the form of toying with a sweeper … and then switching back to a normal slider. Kind of like what his own teammate, Yusei Kikuchi, did this year.
Jansen first started trying to throw a sweeper (the slower, more side-to-side variation of a slider) last season in Boston. He worked on the pitch with Red Sox pitching coach (and former Angels coach) Andrew Bailey, and got some promising results, so he tried to bring it back in 2025 with the Halos.
But he couldn't throw it the way he wanted consistently enough. So during the Angels' series against the Braves at the start of July, Jansen went back to a regular slider -- harder, with more sharp vertical break -- albeit with an adjustment to his grip compared to how he'd thrown his old slider before.
"I'm trying to find something a little bit tighter," Jansen said. "The [newer] slider actually gives me a better, tighter spin, so that it breaks down, and a little bit more velo -- like 84-86 mph. So to me, it's more valuable than what the sweeper was doing. It was just hanging and sloppy and didn't have enough velo. And hitters can stay back and crush that, especially in the late innings."
Jansen wanted to throw a slider that would look more like his cutter to a hitter, but with more drop. His cutter is more of a "rising" pitch that stays up through the strike zone.
"It works because of my cutter," Jansen said. "Hitters need to cheat sometimes, especially when I throw it at 94-95. And if I can have something when I see hitters are cheating, something that goes down, it's hard for them to stop."
The sweeper, on the other hand, was a good pitch when Jansen threw it just right, but his command of it was too sporadic. And when it was off, the sweeper was too different from his cutter -- too slow, too horizontal -- which let hitters tee off on it if he wasn't locating it precisely.
"With the sweeper, you've got to be careful, because if you mis-locate it, it's just an easy [batting practice] pitch to hit," Jansen said. "The bad thing about it is, you go throw it in the game and you punch out a guy with it, and you're like, 'Oh, man. I got it.' And then the next thing you know, it's not consistent."
He likes the new version of his slider better. He used the hard slider to strike out Michael Harris II in that Atlanta series -- he says that's the best one he's thrown all year -- and has since fanned other hitters like Bo Bichette, Adolis García, Riley Greene and Brent Rooker.
"It's doing the job for me right now with the cutter," Jansen said. "It plays out well with the cutter."
Jansen's slider might only make a difference in an at-bat here and an at-bat there. Even since July, he's throwing almost 10 cutters for every one slider. But those few instances where he snaps off a sharp one and fools a hitter who was expecting the cutter one more time, make it worth having in his closer's arsenal.
"It's tough, man, pitching those [late] innings," Jansen said. "Those hitters, they're great. So you need to be consistent, especially in the ninth inning. You have to be at your best. You have to."