Kirby Yates Makes a Very Clear History

I’ve made it no secret that I’ve long admired Rangers reliever Kirby Yates (former Braves reliever Kirby Yates and Padres reliever Kirby Yates), but what he’s doing now has surprised me.

Yates entered Tuesday night’s contest against the Boston Red Sox with a 1.04 ERA; that mark is second among major league pitchers, behind only Emmanuel Clase (another favorite of mine). It’s also Yates’ best career, which is more surprising than it would be for most strikers. Yates already has a season with a low ERA on his resume: 2019, when he posted a 1.19 ERA in 60 2/3 innings, with a 41.6% strikeout rate and a 5.3% walk rate. Pitchers who produce even one season of that quality are vanishingly rare; pitchers producing two are almost unheard of.

The following fun fact represents a mélange of inconsequential strikeouts and points, but that doesn’t make it any less interesting: In MLB history, there have only been 41 instances of posting an ERA of 1.25 or better in a season of 40 appearances or more. Three of those for the year – by Yates, Clase, and Andrés Muñoz – are currently underway.

How many pitchers did it twice? There are only three of them. Mariano Rivera only did it once. So did Jonathan Papelbon, Eric Gagné, Rollie Fingers, and Dennis Eckersley. If Yates sticks around until the end of the season, he’ll join Craig Kimbrel and Wade Davis as the only relievers with multiple seasons under 1.25. And Kimbrel and Davis did it in consecutive years; Yates would be the only pitcher to reach that wagon once, miss multiple seasons, and climb all the way back to the top from sea level again.

As luck would have it, Yates and the Rangers are currently in Boston, where David Laurila had the opportunity to appraise the veteran on his historic pace. Yates said that while he doesn’t like to know his numbers during the year (fair enough; I almost told David not to say anything for fear of jinxing Yates), “If it happens, it happens. Good…But the hard part is that there are six weeks left before the season. Being a bull, a lot can happen in six weeks.”

Indeed, there is no resort where the standards are this high. As of this writing, Yates has allowed five earned runs in 43 1/3 innings. Let’s say he ends the year with 60 innings, which is about what he threw in his last three healthy seasons. In that case, Yates will only be able to allow 2.9 extra runs this year if he wants to stay under his previous career-best ERA. That’s not much margin for error.

The immediate is the final work based on the results. Even the closest person who keeps the local cardiologists in business by going the whole game will end up being treated like a lovable, if slightly eccentric, figure if he keeps turning up the savings. And when you’re talking about the level at which Yates operates — and he does in 2019 — any attempt to find evidence of flexibility just comes off as nitpicking. Still, part of what made Yates’ 2019 season so impressive was his performance.

There are, broadly, two types of intimacy. The first one has such bad stuff — the 100 mph fastball, the knuckle-curve that defies the public — that viewers say, “How do you do that?” This is, by and large, the Kimbrel archetype.

The second depends on the exact order to miss the barrels, sometimes it takes one pitch to save 30 games a year for 10 years. This is Rivera, Eckersley, Kenley Jansen, and so on. These guys aren’t just racking up strikeout numbers, they’re racking up strikeout rates for walks. So while Yates, in 2019, struck out nearly eight batters per walk and posted a FIP of just 1.30, that was almost as impressive as his over-the-top numbers.

This year, not so much. Yates went from the 90th percentile in walk rate in 2019 to the 10th percentile in 2024. His FIP reached 2.14 this year! That’s not really a concern for three reasons: First, there have been 113 seasons in major league history in which a pitcher posted an ERA of 1.50 or higher. Said reliever bested his FIP in 107 of those seasons, more than half of them with earned runs. And two out of six nurses who worked below their FIP did so in just 0.01 runs. Second, Yates is still in the top 10 among professional pitchers in FIP this year. Thirdly, he made the hits this year that he did in 2019.

Yates was already 32 in 2019; you are 37 now. Between his formative years and the three full seasons he spent in the IL, you can expect him to make some adjustments. Maybe he lost some speed or added a third pitch, or changed his equipment. And in fact, he lowered his release point by about two and a half inches, but without the same gains in extension or horizontal release angle.

Either way, when the ball leaves his hand, it goes the same way it did in 2019:

The two pitches are the same, basically the same measurements, the same speed and movement profiles. But while Yates’ ERA has not changed, his walk rate has more than doubled since 2019, while his opponent’s batting average has dropped more than 50 points from his sub-200 start. Yates is on pace for the 10th fewest hits in reliever history with at least 40 innings.

In 2019, Yates was not in the top 20 among pitchers in batting average. He was following Oliver Drake, Tyler Webb, and Trey Wingenter. Brandon Workman – remember him? – Yates scored over 60 points. Brandon Workman!

So how does throwing the same pitches at the same rates lead to the same success in different ways? Let’s focus on where Yates threw it and what hitters did with it:

I don’t know if you’d like to call it a subtle difference where Yates works, but there is a difference. In 2019, he often threw his fastball in the zone — anywhere in the zone, really, with his splitter in the lower end of the zone. In 2024, there is a more vertical split: Fastball up the zone, splitter down. Sometimes down; Not only does Yates throw nearly a quarter of his pitches in the zone, when he throws that pitch, he really buries it:

So I guess it’s no surprise that he goes with a ton of hitters. In 2019, Yates’ splitter was his best pitch. According to Baseball Savant’s run value, Yates’s splitter is one of the 10 most effective pitches in the league among pitches that have been used at least 250 times. His four seamers were very good, but nothing spectacular.

This year, those values ​​are about to be reversed. In 2019, Yates’ average was +3.5 runs per 100 pitches and +15 overall, while his fastball was +1.3 per 100 pitches and +8 overall. In 2024, Yates’s splitter is +1.1 per 100 pitches and +3 overall; his four-seamer is +3.1 in 100 yards and +13 overall.

In other words, by changing his default pitch positions, Yates sacrificed movement to avoid being hit and changed his most effective pitch from a low splitter in place to a fast high. Same guy, same two pitches, same results, very different ways to get there.