he threw fastballs on 78% of his pitches last year, which was 4th most among pitchers with 90 innings. the other guys who did it just have better fastballs, in terms of movement and/or velocity (this is shown in their pitch values on fangraphs). while pomeranz has shown positive value from his fastball, his curve and change had very poor results last year. i guess you can look at this two ways - he's never going to be a good mlb pitcher if his secondary offerings don't improve, but on the other hand, he really wasn't that bad considering that he had only one above-average pitch and he had to rely on it heavily. i think at worst you'd get a dynamic bullpen arm who smashes LH batters, and maybe if his secondary pitches come along then a lot more. but i'm pretty sure the rockies are at the point where they're giving him away for peanuts.