The best pitches for Cardinals' starters and relievers in 2023

Relievers

Ryan Helsley: Slider

Run value: 9
Usage: 36.7%
Batting average against: .113
# of pitches thrown: 223

Ryan Helsley was injured for a large chunk of last season, so he wasn't able to rack up the counting stats like he usually does, but his slider was as effective as ever. He struck out 53.3% of batters with this pitch, and it generated whiffs 52.2% of the time. Helsley's slider topped out at 89 MPH, but it was exceptionally effective against right-handed batters. They hit only .079 against the slider.

Giovanny Gallegos: 4-seam fastball

Run value: -1
Usage: 50.2%
Batting average against: .267
# of pitches thrown: 443

Giovanny Gallegos has one of the worst seasons of his career in 2023. His ever-reliable fastball and slider both failed him last year en route to a 4.42 ERA in only 55 innings. Gallegos was able to maintain a low walk rate last year, but he allowed much harder contact on his pitches, particularly against his four-seamer (92.4 MPH exit velocity). If Giovanny Gallegos can regain the effectiveness of his fastball and slider next year, he can become a force at the back of the bullpen once again.

JoJo Romero: Slider

Run value: 5
Usage: 22.8%
Batting average against: .100
# of pitches thrown: 125

JoJo Romero evolved into the Cardinals' most reliable reliever last year. His slider was his calling card. While it wasn't his most used pitch, it was surely his most effective. It generated whiffs at a 53.2% rate, and it had a K% of 60%. Batter didn't have hard contract against it, and it was his best put-away pitch.

Andrew Kittredge: Slider

Run value: 2
Usage: 37.6%
Batting average against: .174
# of pitches thrown: 70

The St. Louis Cardinals acquired Andrew Kittredge via trade with the Tampa Bay Rays. Kittredge, 33, employs three pitches: a sinker, a slider, and a 4-seam fastball. His slider was the most effective of those three last year. Batters struggled against the pitch, and the pitch had a 39.1% K rate. Kittredge's sinker has historically been his best pitch, but his slider supplanted the sinker last year according to run value.

Keynan Middleton: Changeup

Run value: 4
Usage: 42.9%
Batting average against: .209
# of pitches thrown: 367

Keynan Middleton was signed to a 1-year, $6 million contract this offseason. Middleton will slot in as a middle reliever with the potential to pitch in high-leverage situations. His changeup, a pitch he threw over 40% of the time, was his most productive pitch last year. It generated soft contact (84 MPH average exit velocity) and plenty of whiffs (37.7% whiff rate). Middleton's four-seamer was also a plus pitch according to run value, and only his slider was worth negative value.