As a whole, major league hitters batted .217 against curveballs in the 2018 regular season. Break that number down by each major league franchise and you find the San Diego Padres near the very bottom of the list as one of five franchises who failed to hit above the Mendoza Line against the curve (Washington Nationals led the league with a .249 average).
A number of individual hitters in the San Diego lineup severely struggled with the breaking pitch. Starting catcher Austin Hedges went 2-24 (.083) against the curveball, the lowest average on the team, among all hitters with at least 10 results.