bb/100

The term bb/100 is a technical poker term that describes a player’s average win rate over 100 hands, expressed in the number of big blinds won.

The expression is primarily used by cash game players, who might say something along the lines: “My win rate in online NL50 is 5bb/100.” What this means is that, on average, they’ll win five big blinds over the course of 100 hands played. Which equates to $2.50 won per 100 hands on this particular game.

The bb/100 is the best indicator of one’s success in cash games, while players usually use ROI for measuring tournament results. For this number to be truly relevant, it needs to be calculated over a big sample, i.e., thousands of hands. The bigger the sample, the more reliable it becomes.

This is to say that someone having a ratio of 10/100 over the course of 400 hands is not a relevant number because the sample is too small. On the other hand, a bb/100 ratio of 4/100 throughout 500,000 hands is indicative of the player’s true win rate that they can count on.

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