The key for Alfaro, like Velasquez, is to relax and let his talent take over.
He's so powerful he doesn't have to swing hard, when he just tries to make contact, the ball's gonna jump off his bat.
And he seems to be trying to lay off the bad pitches, though at times I wonder if he can see the spin and pick up breaking stuff. That's key, because if he doesn't get himself out, his power plays into a solid offensive catcher.
Defensively, he's really improved his throws, the rocket arm was always there, but his motion is more compact and his accuracy is much better. And he's really athletic on those dribblers, cat like the way he pounces on the ball.