In his last four starts, Stoner is 4-0 with a 1.04 ERA. In those 26 IP, he's allowed just 12 hits for an opponents' batting average of .140. He's fanned 19 and walked five for a K/BB of 2.71.
The night I saw him in Binghamton, Stoner's fastball was anywhere from 88-92 mph, although it was mostly 89 and 90 mph. He says his fastball was a little quicker earlier in the year. He threw a curve, a slider and a changeup, which he used only sparingly that evening. I wouldn't describe any of his off-speed pitches as "nasty" he did throw them for strikes.