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.