Everything I look for in a prospect comes down to one thing "reaction"

How do they react to the fighter in front of them

How do they react to getting hurt

How do they react hurting the other boxer

How do they react when their style isn't working.

As far as skills go, they can be learned while still in the prospect phase. That's why at prospect level I really like to see what's natural to them. Those natural reactions and a good solid work ethic combined are what make a prospect become a contender.