20 big bets (i.e. 40 big blinds). Let me just check...

Okay, on my best table tonight I won £86.50 in 93 hands for a BB/100 of 186 (yes, I am showing off, humour me ).

Rounding it up to 100 hands, I would have won £93, which means a BB in this case must be £0.50. I play at £25NL, so a Poker Tracker No-Limit BB is equal to 2x Big Blind.