How Real is the Jameson Taillon Turnaround?

[Matthew Trueblood]

His Cubs career couldn't have gotten off to much rougher a start, but the burly righthander has enjoyed great success since late last season, and the surface-level numbers say he's been even better thus far in 2024. Are they right?

Image courtesy of © David Banks-USA TODAY Sports

Over his first 12 starts of 2024, Jameson Taillon has a sterling 2.90 ERA. In 68 1/3 innings, he's struck out 53 batters and walked 16. The Cubs have gotten a lot of disappointing or as-expected performances this year, but Taillon's stands out as one that exceeds the expectations most people held for him coming into the season.

The biggest source of trouble for Taillon last year was a vulnerability to home runs, and he's limited those much better in 2024. On balance, though, his peripheral numbers don't show a huge improvement. On the contrary, his strikeout rate is significantly down. Why? And does that suggest that he's just getting luckier this season than last year?

Well, first, let's address those home runs. Last year, they made up 4.1% of all opponent plate appearances against him. This season, that figure is down to 2.8%. The difference sounds tiny, but firstly, it works out to a difference of about nine homers over a full season, and secondly, the league average is just over 3%. That means that Taillon has gone from allowing significantly more homers than an average pitcher to actively preventing them.

He hasn't done it by forcing opponents to hit the ball on the ground more often. They're elevating at just about the same rate as last season. One change, though, has been where those fly balls go. Taillon hasn't allowed opposing batters to pull the ball as much; they're hitting more of their flies to the big part of the ballpark. Against lefties, especially, he gave up way too many pulled fly balls last season. This year, he's made that much harder for them to do.

Righties are still pulling it fairly often, but that was never Taillon's biggest problem, because he allows much, much harder contact to lefties than to righties. Since the start of 2023, opposing righty batters have an average exit velocity of 85.5 MPH and a sweet-spot exit velocity (the average on balls hit between 10 and 35 degrees) of 88.5 MPH. Lefties, by contrast, have an overall average of 90.9 and a sweet-spot average of 96.1.

Of 130 pitchers with at least 250 batters faced when they own the platoon advantage since the start of last year, Taillon has yielded the sixth-lowest sweet-spot exit velocity. Flip the platoon advantage to the batter and keep the threshold the same, though, and Taillon allows the seventh-highest sweet-spot EV. That's an incredibly stark difference, but it's less dangerous and damning if Taillon can force lefties to hit the ball to the parts of the park where the fences are 400 feet away. It matters much less where righties hit it, because they're not hitting it well enough to go out, anyway.

It also helps, regardless of batter handedness, to allow lower trajectories on the best-hit balls. Taillon has done that this year, too. Here's where he ranked in total sweet-spot exit velocity and well-hit launch angle (the average angle on all balls hit 95 miles per hour or harder) in 2023, along with some players who compare closely.

If you want to be good while allowing a high Well-Hit Launch Angle (WHLA), you have to miss a lot of bats. Spencer Strider speaks for the viability of that set of tradeoffs, but also for the difficulty of it. If you don't throw 100, with a nasty slider and a strikeout rate over 30%, allowing a high Well-Hit Launch Angle will lead to a lot of home runs allowed, even if you stay on the right side of average in terms of Sweet-Spot Exit Velocity (SSEV).

Now, here's the same chart for 2024, with Taillon in a new neighborhood.

Obviously, you want to be in that lower left quadrant of the chart. That means you're better than average in terms of both WHLA and SSEV. Taillon has put himself there, without any decrease in SSEV of which to speak. Opponents' Barrel rate is down against him this year, because when they hit the ball hard, they aren't hitting it as high. As the others highlighted above show, even if you're just barely in the lower left quadrant, it tends to be a very valuable skill set. Taillon is finding ways to minimize damage on contact this year.

Now, let's talk a little bit about his strikeout and walk rates. Taillon has changed his movement profile and pitch mix slightly in 2024, partially to achieve the very effect described above. To righties, Taillon has thrown more cutters and fewer sinkers this year than last. To lefties, it's been fewer cutters, and more curveballs. Part of that is because his cutter is becoming more slider-like; he's not throwing it like the same-plane, in-on-the-handle fastball that makes the pitch effective against opposite-handed batters.

That's not the only change he's made this year, in terms of pitch shape. His sweeper has more depth; so does his curveball. He's not using his changeup much, preferring to lean into those curves against lefties, but when he does throw that change, it's more of a high-rise pitch than ever. All those changes, though, have done nothing to upgrade the individual evaluations of those offerings, and in fact, Taillon is inducing fewer whiffs per swing and fewer swings outside the zone than last year. He's allowing many fewer homers and fewer walks, but he's also down to an 18.3% strikeout rate.

As you might guess, some advanced numbers don't really believe in Taillon, on the basis of all this. His DRA-, at Baseball Prospectus, is 108, a couple points worse than last season, when his ERA was two runs higher. (DRA- is scaled to 100, and lower is better.) Taillon isn't dominating hitters. Yet, he's having more holistic success, and by no small margin. Whether these small changes make his results sustainable, or whether he'll see some regression, is hard to predict. For now, all we can say is that he's been the pitcher they hoped they were paying for a year earlier, and that the Cubs badly need him to keep being that guy.

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