What changes could help trade deadline addition Ryan Gusto reach untapped potential

Ryan Gusto was the headline piece that the Marlins received when sending Jesús Sánchez to Houston on Thursday. Gusto, who is 26, made his MLB debut with the Astros this year. So far in 24 total appearances (14 starts), Gusto has put up a 4.92 ERA, 1.48 WHIP, and 4.11 FIP in 86 innings. On the surface, his numbers have not been impressive.

What made Gusto attractive to the Marlins? His six years of control, ability to command the strike zone, deep arsenal, and underlying individual pitch metrics. There is a lot of untapped potential here.

Gusto comes to Miami will sizable platoon splits. He sets up on the middle part of the rubber and then cuts over to the right side of the mound, releasing the ball nearly pointing at the right-handed batter's box. It's a deceptive look that has helped him hold RHB to a .345 slugging percentage. He confidently fills up the zone against them (4.3% walk rate), but maybe a bit too confidently. Throwing in the middle of the zone still leaves him susceptible to damage. Look how good he is when commanding just off the edges:

Breaking down the arsenal, Gusto throws seven pitches: four-seam fastball, sinker, cutter, changeup, slider, sweeper, and curveball. Five of those pitches currently have whiff rates above 22%. Interestingly, Gusto becomes the third Marlins pitcher on the 40-man roster who throws three different types of fastballs, joining Calvin Faucher and Cal Quantrill, This is a growing trend around the league, as having more pitches allows a pitcher to sequence more effectively vs. righties and lefties. 

According to the FanGraphs stuff+ model, Gusto has three above-average offerings—the four-seam (106 Stf+), sinker (109 Stf+), and slider (110 Stf+).

I foresee the Fish cutting down on Gusto's four-seam fastball and increasing the usage on other pitches. His four-seam does have intrigue and works effectively at the top of the zone. So far this season in the big leagues, he's been averaging 94.1 mph and touching 97 mph, and it has gotten a 30.4 CSW%, which ranks in the 80th percentile. Gusto pounds the fastball high 65.8% of the time, 92nd percentile in HiLoc% among all four-seamers. It plays well with his above-average vert of 17 inches and low VAA (-4.33). 

With natural cut (6.1 inches of horizontal movement), this pitch has great results vs. righties (.119 xAVG, .161 xWOBA, 2.3 barrel%, and 30.3 CSW%). 

Gusto mixes up his arsenal depending on the handedness of the batter. He uses his cutter and four-seam nearly evenly, but elects to throw his changeup and curveball mainly to lefties, and the sinker, sweeper, and slider to righties.

Gusto's changeup seemingly has the most potential as it has been highly effective vs. lefties. It has posted an above-average 54.2 GB% and a low hard-hit% of 20.8%. He throws it hard—88 mph on average—with good spin. This is a pitch that may see a increase in its usage. It may fair well vs. righties as well due to its characteristics.

Gusto's curveball and sweeper have both had mixed results.

The curveball has been hit hard in the air too often with a 56.8 hard-hit%, and .525 xSLG. It has a average exit velocity of 92 mph. The placement of the curveball is in the zone too often (44% zone rate). Gusto may look to change the location of the pitch, or perhaps he just had trouble commanding it. In either case, there is reason to believe this pitch should see its usage dropped.

The sweeper has had slightly better results, but a shocking .629 xSLG because of its 41.9% fly ball rate. Like the curveball, the sweeper has caught the hittable areas of the zone too often. He gets solid outcomes when throwing it low and to the arm side. With other pitchers, the Marlins have successfully introduced/refined their sweepers. In Gusto's case, the keys will be location and adding extra depth on the pitch.

Gusto has also experimented with a tighter slider, that moves horizontally, like his sweeper, but is thrown harder. This pitch has only been thrown 2% of the time, but has shown some promise vs. right-handed hitters. It appears in its low usage that Gusto has better control of the pitch and doesn't throw it in undesirable locations. The Marlins may up his usage of it. 

Lastly, Gusto's cutter and sinker have been poor. Both pitches currently have a minus-3 pitch value, according to Baseball Savant.

The cutter averages 89 mph and doesn't have much movement. It has a 65.7% hard-hit rate and .393 xwOBA, getting a 25% whiff rate. He has thrown it in the strike zone a staggering 64% of the time, ranking in the 95th percentile of cutters. This level of exposure may be leading to the high level of damage on the pitch. It's another opportunity for the Marlins to either change the intended location of the pitch, or lessen the usage of it in general. 

The sinker, which is thrown mainly to righties, has worked as intended to generate ground balls and a good amount of whiff (15.2% so far). The pitch has the lowest fly ball rate in his arsenal besides the lesser utilized slider. It has been pounded by opponents, with a 13.3% barrel rate and 45.2 hard-hit%. Like his other pitches, it has a high zone rate and gets a lot of contact. 

Overall, the Marlins identified a young, controllable starting pitcher with the upside of a No. 3/No. 4 and the floor of a swingman. Ryan Gusto will certainly see pitch design and pitch mix changes, hopefully benefiting like many other Marlins have this season under the tutelage of pitching coach Daniel Moskos and director of pitching Bill Hezel. They have a knack for utilizing deep arsenals to create advantageous pitch sequencing methods. Gusto should fit right in.