Back to the Pittsburgh Pirates Newsfeed

First Pitch: What is the Difference Between a Number Three and Number One Starter?

I got an interesting question today in the comments of my Steven Brault article, asking about the definition of number three and four starters. The question:

"One question I've wondered for awhile is the definition/ skills of the "#4, #3, etc" starter. I understand nothing is equal value across the board, but Dallas Kuechel for example has excellent control is athletic and has a great change up and deception, average fastball. Sounds like a #4 with the upside of a #3 right?
What's the seperator for Brault to Keuchel? or #3 to a #1."

I started thinking about a short answer, but really didn't have one, other than pointing to my article from the start of the 2014 season, breaking down each rotation spot by ERA.