Why does USA amateurs suck at amateurs ? But then shine as a pro ?

[Sleepwalker]

Computer scoring in the amateurs over the past couple decades has had an impact as well. It can be detrimental to boxers who fight with aggression.

In addition, in the Olympics/amateur ranks, a soft right jab that lands cleanly is worth every bit as much as a pulverizing left hook. Amateur fighters aren't given any additional credit for hard-punching, effective aggression or for staggering or wobbling an opponent.