An abbreviation for “Bets When Checked To.” The term is used by online players to suggest a post-flop tendency of an opponent, and is quite often used by overly aggressive fish as they can’t help but try and win every pot.
EXAMPLE “I open JJ from early position. A tricky player on the button calls and everyone else folds. He seems to always bwct on the flop so I will bet even if a scare card does come down.”
If you’re using Holdem Manager, there is a handy “bet in position” stat, which tells you how often the villain bets when checked to.