In urban use this word has been around since the dawn of baby
boomers, but in modern
day it is a widely used gambling term referring to very good
player. Most commonly used to describe professionals in sports gambling. As a descriptive among gamblers you do not describe oneself as a "Sharp", but used to describe others. Sharp can also define the wager to have insight or advantage.
That
player's
won over 20 days straight he's a sharp.
I really like my odds the sharps are on them.
That was a one sharp
play, nobody had it except you.