The curveball has lost some of its bite for Allen, turning from more sharp sweeping action at 87 mph at his career peak, to a more vertically-inclined 83.2 mph offering in 2019. The results have weakened less dramatically than his declining fastball, with hitters chasing (29.1%) and whiffing (14.2%) less than ever but still only registering a .286 wOBA against it.
Allen’s decline over the last 2 years starts with his fourseamer and the 31-year-old will need to sharply reverse trend to get back to his old form. With a loss of nearly 4 mph since it peaked in 2014, Allen used it a career-low 54% of the time and was largely ineffective with it in 2019, allowing a 12/17 K/BB ratio. Though still showing above average rise and armside run, the lack of velocity and location has led to a career-low 6.1% SwStr rate and .784 SLG against it.
Allen’s average fastball velocity continued to decline down to 93.5 mph in 2018, resulting in a career-worst 136 wRC+ allowed for the pitch. With relatively average movement, he’ll have to find a way to regain some of that velocity for his fastball to be effective again in 2019.
This hard curveball functions as Allen’s strikeout pitch, but he allowed more hard contact on it in 2018 with a .132 ISO compared to .060 the previous year. It still had an excellent 18.9% swinging-strike rate and didn’t see much change in movement, though its velocity dipped along with Allen’s fastball.