A expression of winnings in poker cash games, bb/100 refers to the number of big blinds won per 100 hands. Here is the formula for bb/100:
(winnings/big blind amount) / (#of hands/10)
For example, if you’re playing a game with $1/$2 blinds and win $200 over a 1,000-hand sample, your bb/100 would be 10. This would be calculated as:
($200/$2) / (1,000/100)
…which equals (100/10) = 8.75.
Not to be confused with BB/100, which calculates winnings in “Big Bets” (2x the big blind) per 100 hands (though the two are sometimes used interchangeably).