Diamondbacks: 2023 Projected Rotation and Each Starter's Most Effective Pitch

1. Zac Gallen: 4-Seam Fastball

No surprise here, Gallen is #1.  In my article “Diamondbacks: 3 Impressive Stats From 2022” I take a dive into how bonkers Gallen was in 2022.  Among NL pitchers, he was 1st in WHIP and BAA.  Making him one of, if not the most dominant pitcher in the NL.  Sandy Alcantara won the Cy-Young, but Gallen had to have been right on his heels…

According to baseball savant, Gallen mainly relied on 4 pitches last season: 4-seam fastball, curveball, cutter, and changeup.  The pitch he threw almost 50% of the time and his most effective one; the 4-seam fastball.  Gallen’s 4-seam wasn’t just good, it was dominant.  When hitters faced this pitch they hit to the tune of a .165 batting average.  .165!  Don’t get me wrong his other pitches are effective as well, but man, good luck hitting his heater…

2. Merrill Kelly: Cutter

Merrill Kelly had a strong 2022.  He went 13-8 in 33 starts, posted a 3.37 ERA, and finished the season with a 1.14 WHIP.  Any team in the league would love to have a Merrill Kelly in their rotation and the D-Backs are thrilled he’s in theirs…

According to baseball savant, Kelly had a large arsenal and relied on 5 pitches last season: 4-seam fastball, curveball, cutter, sinker, and changeup.  He did a great job at mixing his pitches as he did not throw one pitch more than 30% of the time.  This is a great way to keep the hitters guessing.  The pitch that was most effective for Kelly was his cutter; Kelly’s cut fastball ran anywhere from 89-91 MPH and batters had trouble with it.  Kelly kept batters under a .200 average when throwing his cutter (.197).  With that in mind, Kelly may rely on this pitch more often in 2023 as he only threw it 18% of the time in 2022…

3. Madison Bumgarner: Changeup

2022 wasn’t a fantastic season for the veteran southpaw.  Bumgarner finished the year with a 7-15 record, a 4.88 ERA, and a .281 BAA.  Let’s hope we see a bounce-back season for Madison…

According to baseball savant, Bumgarner relied on 4 pitches last season: 4-seam fastball, curveball, cutter, and changeup.  He mainly relied on his cutter and 4-seam as he threw both a combined 70% of the time.  The pitch that was most effective for Bumgarner was his changeup; running anywhere from 84-86 MPH batters had trouble with it.  Surprisingly Bumgarner only threw his changeup 11% of the time.  Batters were hitting a mere .145 against this pitch!  .145!  Going into this upcoming season, Bumgarner and pitching coach Brent Storm need to realize how effective this offspeed pitch is and find a way to put it into the mix more!  This may result in a lower ERA and BAA for MadBum…

4. Zach Davies: Changeup

Zach Davies put together a solid 22’ Campaign.  In 27 starts, Davies posted a 4.09 ERA.  Davies has always been a reliable starter and that is exactly what the D-Backs got out of him in 22’ and hopefully will in 2023...

According to baseball savant, Davies, incredibly, only relied on 2 pitches last season: a sinker and a changeup.  He mainly relied on the sinker as he threw it 54% of the time.  But combined between the sinker and changeup, Davies only threw other pitches 11% of the time.  The pitch that was most effective for Davies was his changeup; running anywhere from 78-81 MPH batters had trouble with it.  Batters hit a weak .187 against this pitch a season ago!  How does the old saying go?  “If it ain’t broke don't fix it.” Well, if Davies only needs two pitches, then let the man throw two pitches.  Any big-league club would love to have a guy that has an ERA under 4.10!