Detroit Tigers RHP Casey Mize
So last week, Austin Drake, who does the stats for Bally Sports Detroit, posted a comparison of Casey Mize to Justin Verlander’s 2006 rookie season.
It got me thinking about comparing the two different campaigns and what factors they may have in common. As a collective in 2006, the MLB batting average was .269 and OPS was .768 so Verlander was below the league average. Strikeouts-wise, Verlander was not yet the strikeout machine he would later be so he was below the K per 9 league average of 6.6.
For Mize, the league batting average was .244 and the OPS was .728 so he faired well, and as far as strikeouts per 9 go, he finished below the league average of 8.9. From a historical perspective, it is vastly different now than it was in 2006 but regardless, Verlander did pitch more innings than Mize did.
Heading into the season, there were discussions of having Mize start the season down in the minors but he had a strong finish to spring training. What was successful for him this season compared to the few starts he made in 2020?
He cut his walk rate down from 9.8% in 2020 to 6.7%. While the 2020 season is a limited sample size to all these numbers, according to Baseball Savant, cutting back his splitter usage and instead went more with a slider. As a result, batters only hit .195 off the pitch and was able to generate a Whiff% of just 28.2%. Another stat that pops out is that the slider gave Mize a -10 run value which as a result, made his splitter when he did use it, a much more effective pitch.
Getting the first strike also worked in Mize’s favor as he was able to generate a 62.3% 1st pitch strike rate. While you like to see the strikeout numbers be up a little higher (118 in 150 IP), his 3.3 bWAR was valuable to a rotation that saw many injuries early on to Julio Teheran, Spencer Turnbull, and Matthew Boyd.