The GMs don't know either. It's a calculated risk. All these players are a mix of natural athleticism, hard work on body and skills, natural skills (hand eye etc.), body type and size, and mental attributes, how well they feel the game, spacing, motion, decision making and leadership skills, which are both natural and learned.
Often the league has to pick guys mostly on the things that can't be learned. Size, natural athleticism, natural skills and hope for the best. But if you look at what separates the greats, for a few it's attributes they are born with (Lebron, Jordan) but even those guys work very hard on skills and have great mental aspects. Most other great players take above average innate talents and body and separate themselves with hard work and the mental aspect of the game. They make themselves great.
I wanted Clarke for Boston, in part because he's a great athlete, but also because he seems to have a great feel for the game and leadership skills. But I've learned more about Grant Williams than I knew when he was drafted. He was recruited to Harvard and Yale. He graduated in 3 years. He is very sharp, demonstrates great leadership and very much took a reduced role at Tennessee for the good of the team. Brad says "take 3's" and he worked on it and is shooting a high percentage. Will Clarke be better? Maybe. But I can't fault Ainge for valuing the kinds of things that lead to success for most players, that intelligence and work ethic.
