Hayes is the only center prospect who is basically impossible to pass on at 19, IMO. Bol has a lot of question marks, most notably him losing 30 pounds since his foot injury. It's possible to make a case that Goga is either too slow in today's pick-and-roll heavy NBA or that there's too much duplicity with Poeltl, Milutinov and Aldridge. But Hayes has the chance to become that perfect modern day center every team wants in that he can defend pick-and-rolls at a high level and be dynamic enough offensively to keep opponents honest.