How Carson Kelly Fought Back Against Regression (and Won)

Carson Kelly's start to 2025 was going to be sustainable. The Chicago Cubs catcher spent March and April hitting .360, reaching base at a clip over .500, and providing absolutely massive power numbers, to the tune of a .480 isolated power figure. He struck out only six times (9.0 K%) against 15 walks (22.4 BB%) and checked in at an absurd 260 wRC+. Forget catchers: Kelly's start had him as effectively the top overall offensive player (minimum of 50 plate appearances) through the first month of the year.

A dropoff was expected, and for a hitter with a career .307 wOBA and 93 wRC+, you figured it would more closely resemble a cliff face than a rolling hill. But even with that expectation in place, a drop to a .203/.292/.328 line and 79 wRC+ in May stung. It got worse in June, as Kelly turned in a .232/.283/.286 line and 63 wRC+. The power vanished almost entirely, as he went for a .125 and .054 ISO in the two months, respectively. It also wasn't difficult to figure out just why it happened. 

It wasn't simple regression, wherein Kelly was doing some of the same things and running into some hard luck. Instead, it came due to increased aggression on his part. Kelly's chase rate rose from 17.0% through April to 23.5% in May. With that, his contact rate sagged from 83.6% in the first month to 79.2% in May.

On its own, that wouldn't set off alarm bells, if it didn't carry the contact quality along with it. But as the chase went up and the contact went down, the hard-hit rate cratered. Kelly went from a hard-hit rate of roughly 60% in the first month-plus to just 30.8% in May. His BABIP dropped nearly 70 points as a result. So while regression was always going to be in the cards, the path back was reasonably clear: recover the good process he'd discovered in the early going, in terms of both approach and mechanics at the plate.

It doesn't happen often, but things in baseball can sometimes work out the way they're (logically) supposed to. If Kelly could get his plate discipline back in order, then perhaps he could find his way to being a regular contributor at the plate again—especially since he was pressed into increased service due to Miguel Amaya's long-term absence with an oblique strain. That's exactly what's happened since the start of July. 

While there were marginal improvements in the plate discipline game in June, it wasn't until July that Kelly was really able to round back into form. In a way, it's almost entirely on the strength of his Chase%: 

Kelly's chase rate in July is just 11.9%. Unsurprisingly, the rest of the contact trends have come along with it. His 88.9% contact rate tops the Cubs this month, and his hard-hit rate is back to a touch over 48%. Kelly also has his walk rate (14.3%) back above his strikeout rate (8.6%) this month. Even working off a small sample (and with the contact rate coming in higher than we'd expect), there's a clear correlation between Kelly's discipline and his ability to make high-value contact.

There isn't much more nuance than that. Kelly isn't feasting off one particular pitch type; he has individual months of whiff against offspeed more than breaking pitches or months of harder contact off both offspeed and breaking than against fastballs. It's simply a matter of reining in his swing, in order to make solid contact within the strike zone. Even if he's due for a slight regression in the second half of this month (his .333 BABIP reads a touch high), there's a certain simplicity in Kelly's ability to create offensive value that should allow him to continue to do so down the stretch—provided he keeps it steady in matters of the approach.