McHugh's curveball has been his best strikeout pitch this season. The offering has a 19.5 percent swinging-strike rate, and opponents have hit a miniscule .025 with a .075 slugging percentage against it. Part of that owes to the ridiculous vertical movement McHugh gets on the pitch. As shown in the following graph courtesy of Brooks Baseball, McHugh's curveball dropped an average of 9.02 inches in April and 8.61 inches in May. The second graph shows the horizontal movement, which was 8.73 inches in April and 7.73 in May. Positive movement on the curveball indicates how much it moved away from righties and in to lefties.
The sharp movement on McHugh's curveball isn't the only reason it has been so good this year. He has also had great command over it this season. The following heat map shows how frequently McHugh has kept the curveball at the bottom, or beneath, the strike zone.
Moreover, when McHugh spots his curveball at or beneath the bottom of the strike zone, hitters have barely been able to lay off. Of the 118 curveballs that McHugh has thrown at or below opposing hitters' knees, they have swung at 53 of them and come up empty on 29 of those swings. The information is reflected in the two graphs below.
McHugh's curveball has helped make him a fixture in the Houston rotation and made him an asset in fantasy leagues. Despite this, he's widely available regardless of where you play your fantasy baseball. McHugh should be owned in nearly all mixed leagues.