Julio Teheran to join Rome Braves

That’s a good question and I’m not really sure there’s a concrete answer. Obviously, it is tougher, but pinpointing why is hard. I think with any level it comes down to the ability to get away with mistakes. At the lowest levels you can get away with a lot of mistakes, especially as a pitcher, since the players aren’t consistent enough (not that they aren’t good enough, because they certainly are) to take advantage of them every time. Just like how at the highest level you really can’t make mistakes because guys will almost always take advantage of them.
The reality is that the only difference between rookie ball and the major leagues is consistency. The big leaguers can do it every day, every play, the rookie ball guys can do it sometimes, some days. So the step from Rookie ball to Low A probably isn’t really that huge, except that a few more of Teheran’s mistakes will be capitalized on. That’s how a guy is able to move up the ladder, by limiting the number of mistakes he makes.

I’d prefer a title of:

Julio Teheran to join Rome Braves; Heyward called up to Atlanta

He did one season at Danville (this was Teheran’s second), then Rome and Myrtle in his second year. Teheran’s behind schedule, it would seem.