The Cardinals are heading into the season’s final stretch with a lot going right, the Colorado series notwithstanding. In the very least, they control their own playoff destiny over the final two weeks. All facets of the team have performed good to very good throughout the second half. That includes the bullpen, which has been the most reliable component of the team all season long. A major factor in that performance has been Giovanny Gallegos, the once hidden gem that single-handedly evened up the Luke Voit deal with a dominant run for much of the season. His strikeout and walk percentages are elite, as is his ability to induce either called or swinging strikes. The problem is that while everyone was looking at the rest of the team as it improved, the most dominant reliever started to slip. Giovanny Gallegos needs a tune-up.
His problems started during the late August trip to Cincinnati. After a scoreless outing on August 16th, the Reds knocked him around a bit on the 18th. Using that as our dividing line, here are some key metrics for Gallegos’ season:
Giovanny Gallegos, Before and After 8/18
His expected weighted on-base average is exactly the same, but the actual weighted on-base average has increased. If you’d like to know why, look no further than the rest of the table. He’s giving up more contact and getting significantly fewer strikeouts. His CSW (rate of called strikes and whiffs) is still good since August 18th, but shedding nearly 3% in the metric isn’t ideal. His pre-August 18th rate was elite, ranking third best among all relievers. Since then, he’s still well above average, but no longer elite. That gap has been at least part of the loss in his elite strikeout percentage.
In theory, this isn’t a big deal. Hitters and pitchers go through bad months all the time, and relievers are the most volatile of them all because of small samples. In the case of Gallegos, we’re talking about 9.1 innings from August 18th through Wednesday’s game. It’s an absurdly small sample. If nothing else stood out about Gallegos since August 18th, we could move on with our day. Aye, but there’s the rub. There are some other concerns that stand out.
Let’s start with velocity, thanks to Brooks Baseball. Here’s Gallegos’ velocity by pitch and month this year:
The slider has oddly gained velocity as the season has gone on, but his fastball has dipped about one mile per hour since his May peak. Every mile per hour slower leads to less effectiveness. In fairness, we’re talking about a single mile per hour, which is only a concern if it keeps trending down. In short, his velocity isn’t exactly the root cause. It’s the mildest issue for him.
The bigger problem is a little deeper. Here is his vertical and horizontal release point by month:
He’s getting a higher vertical release and less horizontal release across the board, on all pitches. And finally, here’s what it’s doing to his spin axis:
From top to bottom, the slider goes May, April, June, July, August, September. The August and September dots are the highest in the graph while May is the lowest. The spin axis on his slider has increased gradually as the year has continued. The fastball has been quite consistent, but the slider is different. When you’re a two-pitch pitcher, any difference in either of those pitches can cause a domino effect. His slider wOBA before August 18th was .173, a harbinger of doom to opposing hitters. It’s a very respectable .261 since, but that’s a bit of a spike. His fastball wOBA has gone from .217 to .344.
Somewhere in Gallegos’ delivery, there’s a hiccup causing the release to stray from when he was most effective, whether it’s grip or release point. The result has been a slider with a much higher spin axis and a little more arm-side run. Hitters are doing more damage on the slider, and his whole repertoire as a result. He’s also getting fewer called and swinging strikes. Complicating matters in fixing this is the fact that Gallegos has two sliders, one of which naturally backs up on the arm side the way we’re seeing with greater frequency in the last month. In other words, he has thrown this kind of slider in the past. It’s just happening with much more frequency now and it’s getting lesser results.
Again, we’re talking about some ridiculously small samples here. None of this should adjust your opinion of Giovanny Gallegos or the work he’s done this season unless it continues. Think of this information more as a quick tune-up for the most integral reliever for the rest of the 2019 season. Fix the hiccup or the grip, fix the spin axis, and return your shutdown reliever to shutdown status.