Your assertion that this guy has been mistake free in his 2 MLB starts is presumptuous at best. He was allowing about 6.5 walks per 9 last year and had a 6.46 ERA in AAA last year and while he's cut that down to a little over 4BB/9 this year, he's still going to miss frequently. This is the kind of pitcher the Cubs lineup should chew up and spit out in 4, maybe 5 innings. This kid is far from fully developed and it's a near guarantee that long term, Horton is a better putcher than Abel. This is also his 5th year as a pro with 94 starts in the minors and Horton is in his 3rd full season with 36 starts in the minors.