What is a sharp in sports betting?

What is a sharp in sports betting? He made his first bet when he was 15 years old, and he always made money. But he didn't bet like you or me. You know, having some fun with it, shit like that. He bet like a fucking brain surgeon. Place the checks properly. That's the way you do it. He had to know everything, this guy. He'd find out the kind of inside stuff nobody else knew, and that's what he put his money on. Even back home years ago, when we were first hanging out together, he'd know if the quarterback was on coke. If his girlfriend was knocked up. He'd get the wind velocity so he could judge the field goals. He even figured out the different bounce you got off the different kinds of wood they used on college basketball courts. He'd be working on this shit day and night. There was nothing about a game he was gonna bet that he didn't know. Season after season, the prick was the only guaranteed winner I ever knew. I was so good that whenever I bet, I could change the odds for every bookmaker in the country. I'm serious. That was Casino — Nicky Santoro on what Ace actually did for a living: the quarterback on coke, the wind for the field goals, the bounce off every court. Know more than the market, and the market moves when you bet. That's a sharp. A professional or highly skilled bettor whose action sportsbooks respect and track. In plain terms: a sharp bets for a living, and the books know it. When sharp money hits a number, the number moves. “Sharps hammered the under early.” Let's use this example. A sharp group hits Kansas City minus six at several books within minutes. The books react — minus six becomes minus six and a half, then seven. The line moved because of WHO bet, not how many. Lines and prices can differ by sportsbook. Nothing here guarantees a result or tells you to bet. Lines move and books differ. Nothing here is a guarantee or a command to bet — it's how the number works.