Diagnosing Aroldis Chapman’s Wildness
Yesterday, in a game against the Houston Astros, Aroldis Chapman entered the game in the top of the 8th inning and faced four batters; he walked three of them and hit the other. That leaves Chapman with a league-leading 11.37 walks per nine innings, 16 walks and two hit batsmen in 12.2 innings. In his 15 innings last year (including the playoffs) he walked just five batters and hit one.
Obviously these are tiny samples of innings, but going from three walks per nine to over 11 is alarming. His BIS-reported Zone% is down from 43% last year to 38% this year. Here are the locations of his fastballs to right-handed batters in 2010 and 2011 to see where he is missing: