Going into this year, Dunn always feasted on fastballs. That was the pitch he swung and missed on the least(19%), and pitch type values (2.1 wFB/C) rated him as one of the top 15 best fastball hitters in the majors. Changeups were his kryptonite — he swung and missed on them at a high rate (40+%) and they rated as the pitch he performed the worst against.This season, though, things are all weird: Pitchers are throwing Dunn more fastballs (68% vs. 54%) and he can’t get around on them (-0.7 wFB/C). American League pitchers are also pitching him differently, using sliders as their main out-pitch, and Dunn’s strikeout rate has spiked to 40%. …
Fangraphs’ David Golebiewski points at the non-crushing of fastballs too:
The main reason for Dunn’s downturn at the plate is that he isn’t crushing fastballs near as much as in years past.Since 2002, Dunn has performed +1.64 runs better per 100 fastballs seen than the average hitter. That places him 10th among all MLB batters over that time frame. With the White Sox, however, Dunn’s runs/100 value against fastballs is -0.75. He had never posted a negative run value against heaters prior to this year, but the slugger is handling fastballs about as well as Brendan Ryan and Brandon Inge in 2011. Pitchers have taken notice: they’re throwing Dunn fastballs over 67% of the time this season, compared to a career rate of 59%. …
