Jandel Gustave is good and fun

In Wednesday’s seesaw loss against the Cubs, Jandel Gustave came within one pitch of throwing an immaculate innings: nine pitches, nine strikes, three strikeouts. Gustave had been effective before that, but this was an eye-opening performance. Gustave, who the Giants signed to a minor-league contract over the offseason, had a 6.15 ERA at Sacramento this year (though in PCL numbers that’s like 4.15). His call-up was more about keeping him in the organization than needing to get his arm in the majors.

His showing thus far has been evidence of why the Giants wanted to hang onto him. In ten games, Gustave has a 1.32 ERA in 13 2/3 innings. He’s struck out seven and walked two. It’s a small sample, so it doesn’t do a lot of good to judge his talent based on the results, but we can look at his pitches individually.

Gustave throws three pitches: a four seam fastball, sinker, and slider. The fastballs both sit 96 though he’s reached 98.5 with both this season. The slider has more vertical drop than lateral movement which allows him to throw it to lefties.

His best pitch is his four seamer. FanGraphs ranks it as a 70-grade offering though that’s probably lower now that he’s not averaging 98 with it. Gustave’s fastball is a bit unusual as it features high velocity and high spin, but with heavy sink. Typically, a high spin means that a fastball doesn’t sink as much, but not Gustave’s.

So far, Gustave has preferred to throw the four seamer in the upper half of the strike zone, and it’s been his most effective swing and miss pitch. Hitters have come up empty on 22 percent of their swings. Again, it’s a small sample, but looking at the pitch, it’s not hard to imagine that continuing.

With his heavy downward movement, Gustave is bucking the trend and throwing his sinker more often than he did pre-Tommy John. This may be more of a response to his slider losing a bit of its pizzazz, but Gustave has already thrown more sinkers this year than he did in 2016 when he had thrown 100 more pitches overall.

Because Gustave’s sinker has more vertical and horizontal movement, it helps the four seamer play up. If he throws the sinker along the same tunnel as the fastball, the two pitches will split before they reach the plate. It might not help him miss more bats, but it should make both pitches harder to square up. Take a gander at this sequence to Matt Olson.

The sinker and the four seamer come in at the area, but there’s about six inches of separation between the two when they reach the plate. Olson whiffed at the first pitch and fouled away the second instead of putting either roughly middle-middle pitch in the seats.

Gustave’s slider was previously a 55-grade pitch, but it’s closer to average now. His command with the pitch hasn’t been especially sharp, but the downward motion gives him an option to throw to lefties. Without it, he might be relegated to righty-only duty. It’s his one option to change speeds as well, and we can see how effective that is. Here’s how Gustave finished off Matt Olson.

It was a mistake to location; Stephen Vogt set the target at Olson’s back foot, but Gustave hung it at the letters. Olson was geared up for 96 mph because that’s all he had seen in the at bat, so his timing was screwed up.

Gustave has been one of the more effective relievers for the post-deadline Giants. He’s gone from relative unknown to Bullpen Poochie to a matter of weeks. Going forward, it’d be nice to see more strikeouts from Gustave and those should come if he can throw his slider with more purpose. From what we’ve seen so far, he looks like another example of Farhan Zaidi’s ability to find something for nothing.