• Most AAA pitchers are struggling with the automatic called balls and strikes.
To be fair to Peterson and other pitchers at Triple A, the league ERA is up over five this season as pitchers have struggled to adapt to the automated ball/strike system.
In the Pacific Coast League, the league-wide walk rate has jumped from 4.2 BB/9 to 5.1 BB/9 with little change in strikeouts (9.3 K/9 to 9.1 K/9). In the International League, the walk has gone from 4.0 BB/9 to 4.8 BB/9 with the strikeout rate staying steady at 9.2 K/9. I don’t have the means or the time to figure out if the strike zone is to blame but don’t be surprised if a pitcher’s walk rate drops once they get to the majors.
Of the guys with 20 innings in both AAA and the majors, their walk rate has dropped by an average of 0.58 BB/9 (median = 0.71) going to the majors. Looking at the same group of pitchers from last season, pitchers, on average, saw their walk rate increase by 0.10 (median 0.14). I’m not sure how projections are handling the change. Read the rest of this entry »