Jameson Taillon is the 2nd best prospect in Pirates system according to Baseball America. After 23 starts in Class A+, in which he had a 3.70 FIP and 4.02 SIERA, Taillon was promoted to AA.
The 6-6 245 RHP has a 95-98 MPH fastball with good movement. He threw a lot of them low and was surprisingly hittable. Taillon had more success with his fastball up high, although it had less movement. He can also really jam lefties with it. This should keep his platoon splits down. In fact, his platoon splits have been reversed so far this year, as he has actually struggled to get righties out.
At the beginning of the game, his curveball stayed high but had really sharp break. It improved as the game went along and he shattered a bat with it. It almost looks like a slider at times. Taillon should get plenty of grounders when he controls it (he had a 43.3 GB% this year in A+, roughly league average). The curve is a whiff pitch when he throws it in the dirt. He can throw it to lefties and righties and get swings and misses. It is an elite pitch when he throws it in the dirt and the AA hitters stood no chance.
He began the game with very shaky command but really got better as the game went along. Taillon has dominating stuff, and the command is a little rough around the edges but is not bad. While the arm action is somewhat strange, the delivery is very smooth overall. There is nothing to be concerned about there. When you look at his stuff and watch him pitch, it doesn't really seem to add up with the numbers. This has to be because of bouts of control issues. Even his strikeout percentage was slightly below league average. It certainly seems like I got to see him on his best day. It shows that his ceiling is obviously much higher than most pitchers. There isn't really any reason to think that he won't be a good pitcher in the majors. However, there was no real reason for him to be pitching that mediocre in High A. He is just 20 though, a few years younger than most of his opponents.