Madison Bumgarner’s 2023 Is Off to a Rough Start

Madison Bumgarner
Jonathan Hui-USA TODAY Sports

Once upon a time, a Clayton KershawMadison Bumgarner matchup would have been a sight to behold. But when the two lefties squared off on Saturday evening in Los Angeles, it was a decidedly one-sided affair. Kershaw dominated the Diamondbacks, allowing one run and striking out nine over six innings; Bumgarner, meanwhile, was pummeled for five first-inning runs and lasted just four frames. It was the latest in a long line of disappointing performances since the former Giants ace joined the Diamondbacks.

Bumgarner was on the ropes from the beginning. He served up a double to Mookie Betts on his fifth pitch of the game, hit Max Muncy to load the bases with one out, walked the bases loaded after Chris Taylor’s sacrifice fly scored Betts, and gave up a grand slam to Trayce Thompson, who would later add homers off relievers Kevin Ginkel and Carlos Vargas.

By the time the dust had settled, Bumgarner had thrown 31 pitches and was down 5–0. The 33-year-old lefty did pull himself together enough to follow with three scoreless innings, allowing one baserunner in each, but he finished with four walks and four hits allowed, striking out just two and getting just five swings and misses. Including his 10 called strikes, his 17.6% CSW was his fifth-lowest mark from among his 66 starts as a Diamondback; his low was 15.2% (eight called strikes, two swinging strikes in 66 pitches) in a September 27, 2020 start against the Rockies, in which he at least posted five shutout innings, netting his only win of the pandemic-shortened campaign.

Saturday’s bad news went beyond that meager CSW rate. For one thing, old friend Eno Sarris suggested that Bumgarner and Ginkel were tipping pitches:

Even if that hadn’t been the case, the average velocity of Bumgarner’s pitches was down by nearly two miles per hour relative to last year:

Madison Bumgarner Velocity Comparison, 2022–23
Year 4-Seamer Cutter Curveball Changeup Slider
2022 91.2 87.4 78.6 85.5 83.3
2023 89.1 85.8 76.7 83.7 84.4
Change -2.1 -1.6 -1.9 -1.8 +1.1
SOURCE: Baseball Savant

You can safely ignore that positive bump on Bumgarner’s slider, as he threw just one on Saturday. Additionally, the spin on his four-seamer averaged just 2,041 RPM, down 162 from last year and 184 from his final start of the spring, on March 27 against the Guardians. The pitch also got 2.7 inches less horizontal break than last year’s model. The Dodgers didn’t actually do any damage off of Bumgarner’s four-seamer, though hitters last year destroyed it to the point that it was the majors’ second-least valuable pitch according to Statcast:

Least Valuable Pitches of 2022
Player Team Pitch Pitches % Run Value PA BA SLG wOBA
Chad Kuhl COL Sinker 1002 42.2 26 236 .367 .599 .459
Madison Bumgarner ARI 4-Seam 902 33.2 24 202 .326 .606 .449
Patrick Corbin WSN Slider 771 29.4 23 191 .309 .571 .412
Josiah Gray WSN 4-Seam 1018 39.2 22 233 .305 .742 .487
Austin Gomber COL 4-Seam 838 40.7 21 195 .376 .618 .453
Kris Bubic KCR 4-Seam 1143 50.5 20 277 .348 .587 .441
Kyle Bradish BAL 4-Seam 886 44.5 19 229 .321 .539 .420
José Berríos TOR 4-Seam 758 27.9 17 206 .349 .618 .442
Joan Adon WSN 4-Seam 789 65.5 17 208 .288 .529 .414
Dallas Keuchel 3 Tms Cutter 178 15.3 16 48 .455 1.000 .616
Nick Pivetta BOS Curve 834 27.1 16 209 .299 .442 .344
SOURCE: Baseball Savant

If all of this sounds like a pitcher who’s Physically Not Right, the thought crossed the minds of the Diamondbacks. On Sunday, the team sent the 33-year-old lefty back to Phoenix to be evaluated by team doctors, with manager Torey Lovullo telling reporters, “Bum was talking about fatigue postgame last night.” More via

“Information was kind of coming in slowly and we just thought it’d be the best thing for him to get back to Phoenix where our doctors can get a look at him. On the urgency scale, I don’t think it’s very high, but it’s all precautionary at this point.”

“There was nothing major from his standpoint,” Lovullo said Saturday night. “It was more just us asking questions and trying to find out if everything is OK. There was looseness to the breaking ball, and things just weren’t consistent. He’s always around the zone, but there were some big misses today. Red flags go up when we see that, our eyes tell us a story, but Bum was OK.”

Bumgarner underwent an MRI that showed no structural damage, and as Lovullo said before Monday night’s game, he’s on track to make his next start, likely Friday against the Dodgers at Chase Field. But even if he’s got the green light physically, that’s a long way from finding reasons to be particularly optimistic about his 2023 chances. The former World Series hero is coming off a season in which he pitched to a 4.88 ERA and 4.85 FIP in 158.2 innings and set full-season lows with his 16% strikeout rate and 9% strikeout-walk differential (he was 0.2 points lower in both categories in 2020). Meanwhile, his 9.8% barrel rate and 42.8% hard-hit rate were both full-season highs for the Statcast era. Though he made 30 starts for just the second time since 2016, his 0.5 WAR was the second-lowest among pitchers with 30 or more starts, ahead of only the Mariners’ Marco Gonzalez (0.1).

Since joining Arizona via a five-year, $85 million deal in December 2019, Bumgarner has put up a 5.06 ERA and 5.08 FIP in 350.2 innings, netting just 1.2 WAR. Highlighted by a seven-inning hitless outing that didn’t count as an official no-hitter, his best work came in 2021, when he pitched to a 4.63 ERA and 4.67 FIP in 146.1 innings en route to 1.5 WAR; he missed over six weeks that year due to shoulder inflammation, and while he pitched better after the injury than before, his career has continued its downward trajectory.

Indeed, as measured by Stuff+, the quality of Bumgarner’s pitches has been deteriorating:

Madison Bumgarner Stuff+, 2020–23
Season Stf+ FA Stf+ SI Stf+ FC Stf+ CU Stf+ CH Stuff+
2020 92 98 95 75 107 90
2021 86 80 105 102 57 94
2022 80 95 100 87 57 86
2023 66 102 76 72 82

Woof. Obviously you can take this year’s one-game sample with a grain of salt, but as Sarris, the model’s co-creator, wrote, the fastball Stuff+ does capture some signal at this level. Aside from his cutter, which he throws about 28% of the time, Bumgarner doesn’t have a pitch that’s consistently average or better, and at this point, one has to wonder what exactly he and the Diamondbacks, for whom former Astros pitching coach Brent Strom now works, are doing to reverse this rather dismal trend. In an age when pitchers reinventing themselves with new offerings or refinements of old ones seems like a constant, why is none of this is happening for Bumgarner?

On a team that aspires to break .500 for the first time since 2019 but that projects for just 78.4 wins via our preseason Playoff Odds, Bumgarner now stands out as one of the weak links. The Diamondbacks’ rotation placed just 23rd in our Positional Power Rankings, with six Arizona starters — staff ace Zac Gallen, veteran righties Zach Davies and Merrill Kelly, rookie Ryne Nelson, and prospects Brandon Pfaadt and Drey Jameson — all forecast to exceed Bumgarner’s projected 0.3 WAR, the last three of those each with 40–100 fewer innings. In other words, the case that he is one of the Diamondbacks’ best five starters relies upon some combination of reverence for his track record, a desire to justify a contract that looks like a sunk cost, and a need for prospects to get more seasoning. Bumgarner’s World Series exploits are the stuff of legend, but since spraining his AC joint in a 2017 dirtbike accident that cost him three months, he’s managed just a 100 ERA- and 108 FIP- and reached 30 starts only twice. Going by batted ball stats, he’s had an xERA of 5.53 or higher in every season with the Diamondbacks save for 2021.

Bumgarner is the Diamondbacks’ highest-paid player, owed $23 million for this year and $14 million for next year, but at best he looks more like a guy who can eat 140–150 innings at the back the rotation. It’s understandable why he’s begun the year in the starting five as Arizona breaks in Nelson, uses Jameson out of the bullpen, and farms out Pfaadt, who made just 10 starts at Triple-A Reno last year. But if the Diamondbacks are going to turn the corner, they’ll have to reckon with what the 2023 version of Bumgarner can give them. Right now, that doesn’t look like a whole lot.

Brooklyn-based Jay Jaffe is a senior writer for FanGraphs, the author of The Cooperstown Casebook (Thomas Dunne Books, 2017) and the creator of the JAWS (Jaffe WAR Score) metric for Hall of Fame analysis. He founded the Futility Infielder website (2001), was a columnist for Baseball Prospectus (2005-2012) and a contributing writer for Sports Illustrated (2012-2018). He has been a recurring guest on MLB Network and a member of the BBWAA since 2011, and a Hall of Fame voter since 2021. Follow him on Twitter @jay_jaffe... and BlueSky

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11 months ago

Unless he’s already hurt, I imagine they’ll keep running him out there, simply because it will be helpful in managing the innings (and service time!) of Pfaadt, Jameson, Nelson, Walston, and Henry. Some of those guys are already up (as Jay noted), but it’s hard to manage all of their inning simultaneously in the majors. They will want any of those guys who look good contributing at the big league level at some point in May or June or July without risking hurting them by giving them too many innings. So, yeah, they’ll just let him soak some innings until he isn’t physically right (which might be now).