Four straight disaster outings in which Aaron Nola hasn’t seen the fifth inning, and he’s suddenly available on waiver wires. With seven walks and 14 strikeouts in those 13 innings, we already have one clue — his stuff looks unchanged, but something is being lost in translation.
And yeah, if we start our diagnosis with the movement and velocities of his pitches, we start with the head scratcher. His sinker, change, and curve all had the same velocities in that four start range as they had all year. Maybe he lost a half inch of run on some of his pitches, or maybe that’s just the ebb and flow of a pitch over a season.
Well, maybe his sinker is a little flatter and straighter than usual.
That’s maybe important, but more in the context of his entire arsenal than because his sinker is moving less. Nola doesn’t trust his changeup as much as he should, probably, and that means lots of fastballs. He depends on command, that’s how he leads the league in called strikes per pitch.
So the sinker is important, the sinker is a little flat recently, and he’s having walk and command issues. Check out where he was throwing the sinker to lefties early in the year (left), and where he’s been throwing it over the last four starts (right).
Nola went from dotting the outside corner against lefties to throwing it down broadstreet. And this is beyond a half-inch problem, or even an inch. We’re talking about six inches, probably. That’s how your walk rate triples from one month to the next, and that’s how lefties are hitting .486 on balls in play in his last four starts, compared to .263 in all of his starts before those four starts.
This sort of thing seems like a big deal, but at least it doesn’t look like an injury. There’s no missing velocity, his release points are consistent, he’s still living in the zone. None of his pitches is missing, none of his pitches has changed dramatically.
But the fix is less easy on something like this. For a guy that lives on command, having batters stop swinging is a bit of a problem. And in the last five games, that’s what batters have done.
That isn’t to say that there aren’t some fixes available. Since his heat map has moved to the center of the plate, Nola could move on the rubber to shift that closer to the edge of the plate. Most of the other top-ten called strikes guys throw front-door sinkers to the inside against lefties, and Nola doesn’t do that much. If he can command to that side, he should give that a try. Or perhaps there’s a tiny change to his sinker grip to get that extra movement back.
But you have to find it comforting that there’s no fundamental problem with his pitches. He’s still striking out guys at an above-average rate, and still getting ground balls 60% of the time. They’re making a little more contact recently, but not because his curve his soft or he’s lost velocity.
Aaron Nola needs to find a half inch of movement, or find a way to place that sinker six inches to the right of where he’s been throwing it. He should be able to do that, and he’s still ownable in all leagues. Worst case scenario, don’t throw him the next time out, pull up the heat map for the game once it’s in the books, and see if he was able to locate his sinker better. Given that he’s gotten this far on command, it’s doubtful he’s lost that skill for good.
With a phone full of pictures of pitchers' fingers, strange beers, and his two toddler sons, Eno Sarris can be found at the ballpark or a brewery most days. Read him here, writing about the A's or Giants at The Athletic, or about beer at October. Follow him on Twitter @enosarris if you can handle the sandwiches and inanity.