In poker, bum hunting is a practice of targeting weak, usually recreational players, often following them around to sit in games with these players and significantly increasing one’s edge and win rate.
This practice is much more common in online poker, where certain grinders have detailed lists and databases of weak players. Once they see these players log into a poker website, they’ll follow them around and join their tables.
For example, there will be a recreational player who plays a loose and passive style like fish, making him an easy target. Bum hunters will make it a point to track this player and whenever he sits down to play, they’ll join the game.
Bum hunting is generally frowned upon as it makes recreational players reluctant to join the games. They (rightly) feel like they’re being targeted, which significantly reduces the enjoyment they get from playing.