Ronald Acuña Jr.
But it’s also this: What if, by turning a weakness into a strength, Acuña is forcing pitchers to do exactly what he wants them to do, something that goes against the changing nature of Major League Baseball? What would that look like? Let’s go on a journey.
That’s a decline from last year’s 30% rate to this year’s 13% strikeout rate, which is the third-largest drop in baseball.
That’s largely attributable to a massive improvement in plate discipline, as MLB.com’s David Adler recently delved into, and Acuña currently has the fourth-lowest chase rate in baseball.
That is, Acuña has managed to lay off breaking pitches and offspeed pitches outside of the zone to an extent he’s never been able to do before.
So, because Acuña is doing a better job of not swinging at those low-probability non-fastballs, the ones he does swing at are far more productive.
Look how they’re attacking him, or perhaps more accurately, not attacking him: They’re not throwing him breaking pitches as much.
He’s seeing so little breaking stuff that of the 258 players to have seen 250 pitches, only two players are seeing fewer breaking balls — and one of them is Cavan Biggio, who has demonstrated a near-total inability to hit fastballs so far this year.
Just look at what he did to this four-seamer from poor Trevor Williams in Atlanta on April 27.
In fact, if you look at every hitter in the game who’s had at least 30 plate appearances end both on fastballs and not-fastballs, splitting the difference in the production between them, you’ll see that overwhelmingly, they do better against fastballs.
There are a few reasons why strikeouts keep going up and up, but the two largest ones are that fastballs keep getting thrown faster at the same time they are being thrown less often.
Acuña isn’t just doing a better job of laying off the ones he can’t hit, though he’s doing that too; he’s forcing pitchers to barely throw them to him anymore.
We talked about this for some time in the early part of Mike Trout’s career, that he had a hole against high fastballs.