Least valuable pitch: curveball
Smith is primarily an offspeed-centric pitcher at this time of his career, but it is not because of his curveball. A pitch's effectiveness can vary over a career due to many different factors. But Smith's curveball has either been just okay or downright bad across his 11 seasons.
He only threw the pitch 70 times in 2023, but its usage has steadily decreased since the 2021 season. In that three-season span, Smith's curveball has a -5 run value and never had an expected batting average (xBA) lower than .300. Opposing batters jumped all over the pitch once again in 2023, with an 85.7% hard hit rate against it. Inversely, batters whiffed on the pitch 47.4% of the time, fueling the pitch as a boom-or-bust offering from Smith.
The active spin is not very effective; the pitch has a below-average break horizontally and is only marginally better at breaking vertically. All that, coupled with his below-average velocity on the pitch, just makes for a terrible option. Relievers can get by on two pitches for the most part, as Smith does with his fastball and curveball.
The Royals coaching staff has a decision to make regarding Smith's curveball. Do they try to rework his delivery and approach to improve the pitch, or focus time and effort elsewhere? Smith's best seasons, according to fWAR, coincide with two years of an above-average curveball. It is a call that Smith and the coaching staff need to make together, as there has to be a reason he is moving away from the pitch other than its performance.