The 2023 season was something of a disappointment in Toronto, as the club once again was swept out of the AL Wild Card series after a third place finish in the AL East. As the club spent 2023 treading water, several key players such as star first baseman Vladimir Guerrero Jr. (whose struggles MLBTR's Mark Polishuk discussed last month), catcher Alejandro Kirk, and veteran outfielder George Springer all took significant steps back this year. Meanwhile, the pitching side of the roster faced its own challenges. Right-hander Ross Stripling departed via free agency last offseason for San Francisco and while veteran right-hander Chris Bassitt was a capable replacement this year, 2022 AL Cy Young finalist Alek Manoah was not replaced so easily. Manoah, 25, posted a disastrous 2023 season that saw him sport a 5.87 ERA and 6.02 FIP across 19 starts.
With all the shortcomings of the 2023 squad in Toronto, it might seem somewhat surprising that the club managed to post essentially the same season as they did last year. Fortunately, the Blue Jays managed to turn their starting rotation into a considerable strength this year, even as their best arm from last season was pulled from the starting five due to ineffectiveness. While a solid, 11-start return from veteran lefty Hyun-Jin Ryu and a typically excellent campaign from ace righty Kevin Gausman both were major assets, the steps forward taken by right-hander Jose Berrios and left-hander Yusei Kikuchi did the most to return Toronto to contention in 2023, and provide reason for optimism when looking ahead to 2024.
Both pitchers had their first full seasons in Toronto in 2022: Berrios was acquired at the 2021 trade deadline, while the club signed Kikuchi to a three-year deal in free agency ahead of the 2022 campaign. That season was nothing short of disastrous for both players, as each posted an ERA north of 5.00 and the worst full-season fWAR totals of their careers. With Kikuchi under contract for another two seasons and Berrios signed on through 2028, both signings were looking nothing short of disastrous for the Blue Jays after their first year.
Fortunately, however, both pitchers were able to turn things around in 2023, allowing Toronto to absorb the loss of Manoah's elite production much more easily. Berrios saw his 5.23 ERA in 172 innings last year drop to a much more palatable 3.65 figure in 189 1/3 frames. While he was 26% worse than league average last year by measure of ERA+, he managed to post a season that was actually 16% better than league average by that same metric this season. Kikuchi, meanwhile, saw nearly as drastic an improvement as his similar 5.19 ERA (74 ERA+) improved to a far more respectable 3.86 (110 ERA+) figure. What's more, after making 12 of his 32 appearances out of the bullpen in 2022, Kikuchi made 32 starts in 2023, allowing his innings total to skyrocket from 100 2/3 to 167 2/3.
As good as those seasons were, of course, they weren't enough to get the Jays over the hump in 2023. Looking ahead to 2024, the question for GM Ross Atkins and the rest of the front office is a simple one: Just how sustainable were the improvements for their mid-rotation arms? Fortunately for the fans in Toronto, the improvement both players found in 2023 is largely backed up by more advanced metrics.
After striking out just 19.8% of batters faced in 2022, Berrios improved that figure to 23.5% this year while maintaining a low 6.6% walk rate. Both of those numbers are slightly better than his career averages of 23.2% and 7.1%, respectively, which helps lend credence to the idea that Berrios's return to form could be sustainable. Berrios saw improvements in other areas, too, as his BABIP dropped from .328 in 2022 to just .289 in 2023, while his strand rate rose from 70.9% to 76.4%.
BABIP and strand rate are both typically regarded as fluky year-to-year stats, giving them little value when predicting future performance in such small sample sizes. In this case, however, they back up that Berrios's 2022 campaign during which he led the league in both earned runs and hits allowed may have simply been an outlier: Berrios's 2023 BABIP is almost identical to his career .290 mark entering the 2022 campaign. What's more, advanced metrics such as SIERA indicate that not only were Berrios's 2022 and 2023 seasons similar to each other in terms of underlying performance, but they were similar to his body of work throughout his entire career. Berrios posting a 4.13 SIERA in 2022 and a 4.08 SIERA this season. While the 2023 figure is a few points better, both are in the same ballpark as his 4.04 SIERA in seven seasons since becoming a major league regular.
While Berrios's 2023 campaign indicates that 2022 was merely an aberration in what has otherwise been a consistent career as a mid-rotation arm, Kikuchi's season this year seems to indicate a significant step forward. Among 140 pitchers with at least 100 innings of work in the majors during 2022, Kikuchi's 5.62 FIP ranked in the bottom three, only better than Jonathan Heasley and Josiah Gray. While Kikuchi struck out an impressive 27.3% of batters faced, he walked a whopping 12.8% of batters faced. What's worse, those free baserunners Kikuchi offered opposing teams often found themselves scoring on home runs thanks to Kikuchi's fly balls leaving the year for home runs at an astronomical 23.7% rate that was by far the highest in the majors.
Fortunately, Kikuchi's command and control issues improved considerably this year, even as his strikeout rate ticked down slightly to 25.9%. He nearly halved his walk rate in 2023, cutting his free passes down to a 6.9% rate that was actually in the 73rd percentile among all qualified pitchers, per Statcast. Kikuchi also managed to make improvements regarding the long ball, though they weren't as drastic as his cut down on walks. After putting up the league's worst barrel rate of 14.8% in 2022, Kikuchi managed to cut that figure to 9% this season, good for the 29th percentile among all qualified major leaguers.
While that's still below average, Kikuchi's more reasonable 15.3% home run rate allowed him to post a career year in 2023; this year was the first time the 32-year-old managed to post an above average season by both ERA- (8% better than league average) and FIP- (4% better than league average). SIERA, meanwhile, was actually even more bullish on Kikuchi than Berrios this year, as the lefty posted a 3.86 figure that put him in the same range as quality arms like Logan Gilbert and Sonny Gray while outperforming the likes of Corbin Burnes and Blake Snell.
With Berrios once again looking like the quality mid-rotation arm he appeared to be throughout his career in Minnesota and Kikuchi having joined him at a similar status in 2023, the Blue Jays look to be extremely well set up headed into 2024 with a front four of Gausman, Berrios, Kikuchi, and Bassitt in the starting rotation. That should allow them to be aggressive in looking to revamp the club's offense as they attempt to return to the postseason in 2024 and win their first playoff game since 2016.