The Blue Jays took a bit of a risk entering the season with just one left-handed pitcher in the bullpen, but luckily for them, that pitcher ended up being one of their best. Tim Mayza had been one of the team's more reliable relievers over the past couple of seasons, but in 2023 he took his game to another level. His 3.28 ERA over 2021-2022 was more than halved this year, as he posted a 1.52 ERA in 53.1 innings pitched, which ranked sixth in MLB among all pitchers with at least 50 innings. That's just scratching the surface of what Mayza did in 2023 though, so let's dig a little bit deeper on his career year.
One thing that's very important when talking about Mayza is his role with the Blue Jays. Given how good his raw numbers were, especially his 281 ERA+, you might wonder why he wouldn't be challenging Jordan Romano for the closer role, or why he isn't at least seen as the team's primary setup man. This is because Mayza is essentially just a matchup pitcher, meaning if the other team has a left-handed batter coming up, Mayza's their go-to guy, but if a righty is coming to the plate, the Jays are probably trying to get him out of the game as quick as possible. This role is reflected in his splits, as he faced 115 lefties compared to 100 righties. Accordingly, his numbers against lefties are significantly better, as they only slashed .246/.270./.291 with a 53 OPS+ and his 0.59 ERA against them was the best in the majors (minimum 30 innings pitched). His numbers against righties, however, were below average, as he allowed a 105 OPS+. This makes his potential usage very limited, which is important to consider when discussing him.
When you think of dominant left-handed relievers, names like Josh Hader or José Alvarado probably come to mind. But unlike those guys, who both have K/9 over 13, Mayza is right around the league average of 8.7 at 8.9. What made him so successful was his ability to induce weak contact, particularly groundballs. This is reflected in his peripherals, with a barrel rate and groundball rate in the 94th and 97th percentiles per baseball savant. They even had his sinker, which he uses 75% of the time, ranked in the 93rd percentile for fastball run value, showing how effective he can be without overpowering stuff.
Looking ahead to 2024, while there's every reason to expect Mayza to once again be a solid piece of the bullpen, we probably shouldn't anticipate his numbers to be this elite again. After lowering his ERA below 1.00 in late August, he posted a 4.50 and allowed a .907 OPS over his final eight innings. This isn't to say he'll be bad, but just to set expectations at a reasonable level. An xERA in the 81st percentile and a 2.60 FIP, which ranked 10th among relievers, suggest that he'll still be very good in 2024, but maybe just not as good.
Looking just at this season, not only did Mayza's 2023 stack up great among other MLB relievers, but statistically it ranks as one of the best seasons in Blue Jays history. His 1.52 ERA was the second lowest in team history among pitchers with at least 40 innings pitched, behind only B.J. Ryan's 1.37 in 2006, a number he was set to beat had he not allowed a Junior Caminero home run in his final appearance of the year. He might not be the biggest name, but in 2023, Mayza was incredible, and an integral piece of one of baseball's best pitching staffs.
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