Bullock and Diamond are both pitchers, and there the similarities essentially end.
- Bullock is right-handed, Diamond a southpaw.
- Bullock has one pitch, the fastball; Diamond has a legitimate repertoire.
- Bullock has trouble throwing strikes; Diamond has a good control record
- Bullock has a power arm; Diamond throws harder than you or me, but may be a bit below major league average.
- Bullock was a second-round draft pick; Diamond was signed as an undrafted free agent.
- Bullock is strictly a reliever; Diamond has been a competent (or better) starter as he climbed the Braves ladder.
- Because of the reliever/starter difference, Diamond has thrown more innings in any of his three professional seasons than Bullock has in his entire pro career.
Pretty much everybody outside the Twins organization sees Bullock as the better prospect. Baseball America listed Bullock as the Twins 15th best prospect, Diamond at No. 29. John Sickles doesn't list them in any specific order, but he gave Bullock a B- grade, Diamond a C+. Seth Stohs had Bullock at No. 23, Diamond at No. 28. Aaron Gleeman had the widest disparity: Bullock at No. 10, Scott Diamond at 36.
Obviously, the Twins decided they'd rather have Diamond than Bullock.
Now, a necessary caveat: I don't know what the Twins are specifically basing that decision on. I have some observations and interpretations.
- The Twins have had Bullock in their system for a bit less than two years and they had Diamond in camp all spring. They know more about these two than any outsider does.
- No organization does better at teaching fastball command than the Twins. But Bullock's walk rates have gotten worse at each step up the ladder.
- Diamond increases by infinity the number of left-handed starter candidates in the Twins upper minors. They had none before this deal.
If the Twins had concluded that Bullock was never going to locate his fastball and/or develop a quality secondary pitch, trading him is a lot more explicable than it appears off his track record. If the Twins had concluded that they really need a left-handed prospect at the upper levels, Diamond's value to them was increased.
The Twins are generally as patient as anybody with pitchers. They haven't always been right on the pitchers they've kept or acquired, but few of the ones they've discarded in the past decade or so truly haunt them.