Sharp betting done by sharp players otherwise know as ‘wise guy’ is when the player is betting always to their advantage. Sharp players are looking for bad lines, and mistakes in the lines. They normally are exposed after winning several bets and only then does the sportsbook take action against them.
Although betting to your advantage by doing sharp betting is not illegal, it over the long term can and will result in the sharp player having their account closed as it simply as seen as a large risk for the sportsbook to have onboard. A sharp player normally is a player a sportsbook does not want to have.
There are some sportsbooks such as 5dimes. pinnacle and lovwig who ask for players who think they are sharp to bet with them and openly welcome them.
You are not considered a sharp player simply by winning a few bets. You are considered a sharp player by going after bad lines, moving lines and buying picks to take advantage of the sportsbook.
Definition of a sharp player according to wiki
Handicapping, in sport and games, is the practice of assigning advantage through scoring compensation or other advantage given to different contestants to equalize the chances of winning. The word also applies to the various methods by which the advantage is calculated. …
Sharp players on the whole can damage the experience for the regular square gambler as the sharp player are only looking to expose and use weaknesses demonstrated by sportsbooks for their advantage. In some cases this allows them to bet on both sides so no matter what the outcome is they win. It may sound good winning as a sharp player but the truth is these sportsbooks will just refund the bet and close the account.
If you are betting on soccer for example a good site to use is betbrain which always exposes the best lines and where the best place is to bet. Sharp players use sites like this to their advantage as the research efforts have been done by someone else.