Quote Originally Posted by bitorocha View Post
Any hand that looked like a favorite to win can end up losing as more cards are dealt, but bad beats usually involve one of two scenarios:
The player who wins on a bad beat is rewarded for mathematically unsound play. Calling a bet despite having neither the best hand nor the right pot odds or implied odds to call, then winning anyway, is characteristic of this type of bad beat. It can also involve the inferior hand catching running cards when it requires two cards in a row to come from behind to win the pot. For example, catching cards on both the turn and the river in Texas hold 'em that complete a straight or flush.
Bad beat - Wikipedia, the free encyclopedia

same verbiage from a post from Tmrllncaof (see link below)

What is a bad beat ?

... and yet another post that seems that was similar in this thread...

Bad Beats - PokerSchoolOnline Forum