This is a synonym for an advantage, commonly used in reference to sports and sports betting. It can be applied to the person making the wagers, a team being wagered on, or a player on the team being wagered on.
An edge can be any piece of information a gambler uses to gain an advantage over the house when placing a bet. For example, if a gambler has inside information from team officials that a player is injured or will not play their usual role, that is a big advantage. Many sportsbooks and bookmakers use historical data and any available information to gain an edge over those placing bets. If a player on a team has a favorable matchup or valuable information about their opponent, the athlete is considered to have an edge. Furthermore, talented superstar athletes like that of Michael Jordan or Kobe Bryant give their team an edge because of their ability.