There may not have been a more polarizing reliever among the Atlanta fanbase in 2023 than Kirby Yates. The former All-Star and National League saves leader (2019) saw his return to full-season action with the Braves in 2023, after missing the entirety of the 2021 season and making just nine appearances for the Braves in 2022.
The Hawai’i native, and brother of former Atlanta reliever Tyler Yates, was signed by Atlanta at the end of November in 2021 after missing the entirety of the prior season due to injury. His contract was a two-year deal worth $8.25 million in total with a third-year club option that came with a $5.75 million salary or a $1.25 million buyout.
Originally drafted in 2005, Yates didn’t end up signing with a team until 2009, and didn’t make his MLB debut until 2014 with the Tampa Bay Rays at age 27. After bouncing around between several teams, he found a home in the Padres’ bullpen in 2017, and ended up appearing in 186 games from 2017 to 2019.
What were the expectations?
Yates was a bit of an unknown coming into 2023, because he had made just 15 appearances and completed just 11 1⁄3 innings over the past three calendar years. There was theoretically the upside of a high-leverage, high-strikeout right-handed reliever who could possibly step into the role vacated by Luke Jackson’s departure to the San Francisco Giants in free agency, but the likelihood of realizing that upside was highly uncertain. An uninspiring sign was that, despite the teeny sample size of his 2022, he was clearly out of sorts, tallying -0.2 fWAR with a terrible pitching line. Taking all this together, along with the fact that Yates would be pitching his age-36 season, made it hard to expect much of anything from the veteran. The Braves clearly gambled on him realizing a return to form, but that doesn’t mean it was probable or even reasonably likely.
Still, you can see why they wanted to roll the dice. In 2018 and 2019, Yates was among the best relief pitchers in baseball, totaling 5.2 fWAR, while appearing in 125 games and pitching 123 2/3 innings while posting a 42 ERA-, 46 FIP-, 58 xFIP-, essentially video game numbers. He tallied 53 saves, 41 of which came in 2019 when he was an All-Star and finished ninth in the NL Cy Young voting.
As stated above, there may not be a more polarizing pitcher from 2023 than Yates. He had a 74 ERA-, and 1.1 RA9-WAR, both of which are very good... so someone inclined to not look past ERA might think he had himself quite a successful season. But, ERA isn’t a particularly useful reflection of how well someone is pitching, and the flip side was that the metrics more focused on pitching quality were far less sanguine. Yates managed a 107 FIP-, which is a pretty poor mark for a reliever, and the 99 xFIP- isn’t anything to write home about either. For those partial to mixing quality of contact into pitcher evaluation, his xERA was between his FIP and xFIP, so not much relief there.
Baseball Prospectus has some nifty-but-arcane stats for pitchers, and those had him somewhere around seven to nine percent better than league average. That’s not bad, per se, but it’s also not very exciting — for comparison, that’s around what Jackson Stephens and Brad Hand managed in terms of the FIP and xFIP in their brief time with the Braves in 2023.
All in all, because of the high FIP, Yates compiled -0.1 fWAR during the 2023 season, in stark contrast to his RA9-WAR. He also finished the year with negative WPA and nearly as many meltdowns (11) as shutdowns (12). The ERA was really the only thing you could point to if you wanted to say he had a good year.
What went right?
First and foremost, for Yates, he stayed healthy and was able to pitch the entire season. Beyond that, as mentioned immediately above, he somehow duped the baseball gods into blessing him with an awesome ERA despite not actually pitching that well.
His splitter was a serious weapon, with a sub-.300 xwOBA-against and a whiff rate well north of 30 percent. His fastball got hit fairly hard because of poor location, but generated a lot of whiffs and was mostly thrown to the same unideal place over and over. Yates really didn’t command his splitter well, but it had such excellent shape that it really didn’t matter. As a result, his strikeout percentage was great — in the 94th percentile according to Baseball Savant — only a few points off his peak in the late 2010s. The average velocity on his fastball - 93.6 mph - was almost identical to his pre-injury years.
It’s also worth calling out his June, a stellar calendar month in which he dominated. For at least one month in 2023, he reprised his former video game numbers, with a 51 ERA-, 64 FIP-, and 54 xFIP-. The only downside to that month was that of the three non-dominant outings he had, two came in big situations, though the Braves won one of those games anyway.
But, he had some nice moments aside from June, too. On September 11, he picked up an extra-inning save by mowing the Phillies down, in order, after the Braves took the lead in the top of the tenth to respond to Bryce Harper’s game-tying two-run homer off Raisel Iglesias in the ninth. And, sometimes, his splitter paid dividends even when not getting whiffs, like this play:
What went wrong?
Walks and home runs. That’s the short version, and that was enough to tank his pitching line.
In 2023, Yates threw 56 percent of his pitches outside of the strike zone. League average was 51.1 percent. The splitter was often obviously not going to come in for a strike or anywhere close; the fastball was generally thrown around the belt, rather than high enough to really play off the splitter. Yates got sufficient whiffs, but a low zone rate combined with a low chase rate leads to a lot of walks, and the fastball was thrown in a location prime for being elevated.
This is pretty much a perfect example of what Yates’ fastball did (or didn’t do, depending on your perspective), all season:
These issues were ultimately too much to overcome. Given that the days of pitcher evaluation being based on ERA are long behind us, there’s a good chance that teams look askance at Yates’ services this offseason — just as the Braves did when they opted to take the buyout on his deal rather than sign him up for another year.
It’s also worth noting here that Yates largely toiled in low leverage, as 32 of his 61 outings saw him enter the game in a none-too-relevant situation. Meanwhile, he had six high-leverage entrances... and those six outings were evenly split between shutdowns and meltdowns.
Yates will be pitching in his age 37 season in 2024. Though his 2023 was not good in terms of pitching quality, the xFIP wasn’t horrible, and the preliminary Steamer projections see him as somewhat better than replacement level for 2024, which is kind of impressive given that he actually hasn’t had an above-replacement season for 2019.
Everything really hinges on the same things that doomed his 2023, though. If he keeps up the belt-high fastball and a splitter that misses way too much, he’ll just be a depth option to eat lower-leverage innings. If he manages to get chases the way he did in 2018-2019, however, then he’ll probably make whichever team signed him pretty happy.