The two pitches that swept the Cardinals offseason acquisitions

For the last few years, the St. Louis Cardinals have been behind the curve when it comes to keeping up with the rest of the league. They were behind when using sabermetrics, and they were late to the party when targeting pitchers who strike batters outs. Most recently, the Cardinals were slow to adjust to pitchers and organizations on a new pitch: the sweeper.

The St. Louis Cardinals acquired nine pitchers this offseason. Of those nine, three are penned into the rotation, and at least one will be in the bullpen. Sonny Gray, Lance Lynn, and Kyle Gibson will all be in the rotation, while at least Andrew Kittredge and possibly Nick Robertson and Riley O'Brien will be in the bullpen.

There are some similarities between the sub-categories of these pitchers; Kittredge, Robertson, Victor Santos, Ryan Fernandez, and Riley O'Brien all have connections to the Cardinals' newest front-office member: Chaim Bloom. Additionally, many of these players feature either a sweeper or a sinker as their primary or best offering.

Riley O'Brien, and Andrew Kittredge both use their sinkers as their primary pitches, and Sonny Gray Kyle Gibson, Nick Robertson, and Lance Lynn feature their sweepers as their go-to pitch. It is clear when evaluating the team's acquisitions this offseason that the sweeper and sinker were two pitches the Cardinals wanted to improve upon from last year.

In 2023, only four Cardinals pitchers threw a sweeper, and only Drew VerHagen threw it with any success. His 31.1% usage rate made it his most used pitch. VerHagen was eighth in all of baseball in run value on his sweeper, and batters hit a measly .128 against the pitch. VerHagen had a modest 35.8% K rate on this offering. The Cardinals missed their chance to resign VerHagen. Casey Lawrence, Jake Woodford, and Drew Rom also threw a sweeper to various degrees, but not one of those pitchers had a positive run value on the pitch.

The sinker was a much more common pitch for Cardinals hurlers in 2023; twelve different pitchers threw a sinker, and players like Steven Matz, Jake Woodford, John King, and Dakota Hudson used it as their primary pitch. For as common as the pitch was in St. Louis, it was just as ineffective when looking at run value. Steven Matz threw the pitch 56.1% of the time for a +8 run value, but his sinker was the only one with positive results on the staff. Batters hit only .240 against it, and Matz limited hard contact, as the average exit velocity against his sinker was only 89.6 MPH.

Adding pitchers who feature sweepers and sinkers seemed to be a focus for John Mozeliak this offseason. Let's take a look at the pitchers added who use sweepers and sinkers often.

Sinker

The second pitch that appeared to be a focus for the Cardinals in their pitcher acquisitions this offseason was the sinker, a pitch primarily known for inducing groundballs. Sinkers aren't known as strikeout pitches, but they do have decent velocity typically with strong diagonal movement.

Andrew Kittredge and Riley O'Brien both feature a sinker, and both players will likely make the Opening Day roster as relievers. Andrew Kittredge used his sinker 48.4% of the time last year. It had a negative run value (-3), and batters had a .333 batting average against and .428 wOBA last year against his sinker. Historically, his sinker has been his best offering, including in 2021 when he made the All-Star team.

Riley O'Brien has recently revamped his sweeper. Blake Newberry discussed O'Brien's addition to the roster quite well in his piece at VivaElBirdos. O'Brien builds his arsenal around the effectiveness of his sinker. He allows soft contact off the pitch (86.4 MPH exit velocity), and his curveball plays well off of it.

The pitch sits 95 mph with over 15 inches of arm side run (15.3 inches) and does a fantastic job of keeping the ball on the ground with a whopping 66.7% ground ball rate this year.

For a team that has been behind the curve for half a decade on baseball trends both analytically and practically, the Cardinals jumping on pitchers who feature sweepers and sinkers is a big deal. Sonny Gray, in addition to bringing along his sweeper, is working to transform the way the Cardinals' pitching staff operates. In his interview at the Winter Warm-Up, Gray discussed these changes.

(Mozeliak) would say, "Can you tell me more about that?" So then he went down the pitching department and the people that were here. And I would say, "Well, what about this? Do you have a guy for this and this?" And he said, "No, tell me more about that."

The Cardinals are making big changes to their coaching staff and player personnel this offseason. Hopefully, the team can reap the benefits of these new pitchers who all seem to be connected based on a couple of pitches and a former President of Baseball Operations-turned special advisor, Chaim Bloom.