Giants Take a Flier on Tyler Mahle

New Year’s Eve is a great time to agree to an eight-figure contract; you’ve already got champagne handy to celebrate. Congratulations, then, to Tyler Mahle and the San Francisco Giants on killing two birds with one stone.

Mahle is one of baseball’s great “I can fix him guys,” a status reflected in his contract structure: $10 million guaranteed over a single year, with an additional $3 million available in performance incentives. In 2020, the right-hander struck out 29.9% of the batters he faced over the pandemic-shortened season. The following year, he made 33 starts, threw 180 innings, and posted 3.9 WAR.

By WAR and strikeout rate, Mahle was one of the 30 best pitchers in baseball that year; squint and you could see an Aaron Nola– or José Berríos-type no. 2 starter. That’s what the Twins were thinking, presumably, when they sent three players (including Spencer Steer and Christian Encarnacion-Strand) to Cincinnati for the privilege of employing him. It didn’t go well.

Mahle’s shoulder started barking almost immediately, limiting him to token involvement in the Twins’ playoff run in 2022. Then his UCL gave out in April 2023, ending his career in Minnesota after nine starts.

The Rangers, fresh off a World Series title in 2023 and dealing with a litany of pitching injuries themselves, swooped in with a backloaded two-year contract that winter, figuring Mahle would help out in the latter stages of their title defense and return to previous form for 2025.

That didn’t quite pan out either. Between his Tommy John recovery and yet another shoulder injury, Mahle made just three starts in 2024. (Not that it mattered, as Texas no-showed its post-championship season.) More shoulder fatigue punched a three-month hole in the middle of Mahle’s 2025, but when available, he tantalized.

In 16 starts, Mahle posted an ERA of 2.18. Among pitchers who threw at least 80 innings out of the rotation, only Nathan Eovaldi, Trevor Rogers, and Paul Skenes had a lower ERA. Getting even half of a season like that for $10 million (or even $13 million) would be the deal of a lifetime for Buster Posey and his merry men.

But if you so much as think about popping the hood on Mahle’s season to look at the underlying numbers, things get really weird.

Mahle’s repertoire hasn’t changed too much since 2021; he’s got a four-seamer that owes its effectiveness less to velocity than to superb two-plane movement. Mahle uses that to set up a mid-80s splitter with similar arm-side movement but more drop, as well as a mediocre slider/cutter combination that bleeds together sometimes.

Five years ago, Mahle had average fastball velocity; now that he’s in his 30s, is on his second UCL, and has to go on the IL if he even sleeps on his shoulder funny, he’s lost two miles an hour off his heater, while the league average fastball velo has gone up.

Fastball velo isn’t the whole proverbial ballgame, but throwing harder does make a pitcher’s life easier. For example:

Back in the good old days, Mahle was getting strikeout and whiff rates that were (I’m simplifying here to avoid bombarding you with numbers) around the 80th percentile. In 2025, he had a 23rd-percentile K% and a 32nd-percentile whiff rate. This is, suffice it to say, no longer a big strikeout guy, low-2.00s ERA or not. Mahle is also not now — nor has he ever been — a George Kirby-level avoider of walks.

And yet his FIP in 2025 was 3.37, which isn’t as good as his ERA (which I think everyone except Mahle’s agent would concede was at least a little fluky), but is still quite good. What’s the third ingredient in FIP? That’s right, home runs, of which Mahle allowed only five in 86 2/3 innings.

Mahle arrived in Texas with a career HR/9 rate of 1.39 and a career HR/FB ratio of 14.6%. In 2025, those numbers were 0.52 and 4.9%, respectively — third lowest and lowest among the 138 starters with 80 or more innings.

Despite throwing a splitter as his no. 1 secondary pitch, Mahle is a fly ball pitcher. Not to the extent of, like, Shota Imanaga or Andrew Abbott, but the fly ball bias in his game has been pretty durable. It’s what happens when you throw a fastball that misses barrels up instead of down.

I think it’s fair to expect Mahle’s home run numbers to drop in San Francisco just based on park factor; the Rangers’ home ballpark is pretty neutral for home runs, while the Reds’ is the closest thing to Coors Field you can get east of the Mississippi. And speaking in generalities here, Mahle did a better job of burying his splitter and cutter down and on the glove side of the strike zone in 2025.

It’d be pretty easy to look at Mahle holistically and paint him as a hard-contact suppressor now. He’s always been a fastball movement-over-velo guy, and now that he’s an old, grizzled vet, he’s gotten better at the nuances of pitching, avoiding barrels rather than missing them altogether.

Except the numbers don’t bear that narrative out. His xwOBACON in 2025 was .360 and his HardHit% was 37.1, both within a tenth of a percent of his career average. Mahle’s xERA, 4.27, was nearly a run higher than his FIP and more than two runs higher than his actual ERA. So yeah, anyone expecting those 2025 numbers is going to be disappointed going forward.

Nevertheless, I like this signing quite a bit for the Giants for four reasons.

First: The Giants, having just signed Adrian Houser last month, are making a run on starting pitchers I like despite a lack of empirical backing. Which you’d think would make me more confident, but I’m always a little nervous when a front office’s taste in players aligns too closely with my own, because they’re supposed to be smarter than I am. I remember in 2014, the Tigers spent a ton of draft picks on college players I was really high on: Joey Pankake, Adam Ravenelle, Artie Lewicki, and about five others. Detroit then went on to miss the playoffs 10 years in a row. In short, if San Francisco signs Germán Márquez, it’s gonna freak me out a little.

Back in the realm of the rational, $10 million for a starting pitcher with any recent history of decent performance is a perfectly acceptable expenditure. Given the choice between spending $10 million on Mahle or $12.5 million Dustin May, which the Cardinals did, I’d pick Mahle every time.

Reason no. 3: Let’s grant the premise that Mahle’s career-best home run avoidance numbers were the result of moving from Cincinnati to Arlington. (His stopover in Minnesota was too brief to count.) Wouldn’t it then seem like a good idea to tie him to a home ballpark with a huge outfield and a constant headwind?

And finally, Mahle has endured huge physiological changes over the past five years due to aging and injury, but he’s mostly throwing the same stuff he’s been throwing since his breakout season in 2020. Now, he’s going to a coaching staff that has big opinions on pitching pedagogy.

In my writeup of the Giants’ hire of Tony Vitello, I went into some detail about two assistants he leaned on during his time at Tennessee: strength coach Quentin Eberhart and pitching coach Frank Anderson. Those guys turned Tennessee into a pitching factory, and both of them followed Vitello to San Francisco. I would be surprised if, come Memorial Day, Mahle is still throwing the same four pitches the same way. In fact, if the Giants’ new starter is open to suggestions for how to change his game, you might say that he’s Mahle-able. (Thank you, thank you.)

All that said, the Giants still have plenty of work to do this offseason, because if the goal is to put a scare into the Dodgers, well, this rotation isn’t gonna cut it. Right now, Mahle and Houser slot in behind Logan Webb and Robbie Ray, which gives San Francisco, I dunno, 1 1/3 starting pitchers who ought to scare the Dodgers? As a no. 5 starter with upside for more, I like Mahle a lot on this deal. If he’s the Giants’ Plan A to be their no. 3 starter, they’re going to need a lot of things to go right if they want to compete.