http://www.bluebirdbanter.com/2015/3/27/8287495/aaron-sanchez-strikethrower
"The best proxy for strikethrowing is Zone%, which happily is available on leaderboards (under plate discipline) at Fangraphs, making it easy to see how Sanchez stacked up and to evaluate Anthopoulos' claim. The league average Zone% for relievers was 45%, at 41.9% Sanchez ranked 168th of 209 relievers with 30 relief IP in 204. That puts Sanchez at the 20th percentile, roughly a standard deviation below average (assuming a roughly normal distribution). Not exactly what one would expect of a bona fida strikethrower."