What BB/100 means
BB/100 normalizes win rates across stakes. A player winning 5 BB/100 at $1/$2 has the same per-hand skill edge as a player winning 5 BB/100 at $5/$10 — the dollar amounts scale, the underlying rate does not.
Typical realized win rates for winning regulars:
- Microstakes online cash: 5–12 BB/100 (high rake handicaps; rakeback closes the gap)
- Small-stakes online cash: 3–7 BB/100
- Mid-stakes online cash: 1–4 BB/100
- High-stakes online cash: 0.5–2 BB/100 (very tough games)
- Live cash: 8–20 BB/100 (much softer than online; smaller samples)
Why the confidence interval matters
Your realized win rate is the average of your random results so far. Your true win rate is the long-term expectation that average will converge to. They are not the same number unless your sample is huge.
The 95% confidence interval makes this concrete. If you have run +5 BB/100 over 10,000 hands with standard deviation 100, your true rate is very likely (95%) somewhere between -1 and 11 BB/100. That is a huge range — and it includes "small loser." Most players who think they have a 5 BB/100 win rate after 10k hands are wrong; the honest answer is "somewhere between -1 and 11."
The interval narrows roughly with the square root of hands. Doubling hands does not halve the interval — it narrows it by about 30%. To go from a 12-BB-wide interval to a 3-BB-wide interval, you need 16× the hands. This is why patience matters more than intelligence in win-rate analysis.
How to use this in practice
- Track your hands and net BB at every stake.
- Recompute confidence interval at every milestone (every 10k hands).
- Do not move up until the lower bound of your confidence interval is comfortably positive — that means you are very likely a winner, not just running well.
- Use the confidence interval, not the point estimate, when deciding whether to switch stakes or formats.
