Simulate 1,000 possible futures for your win rate. See realistic downswings, how wide your results can spread, and the bankroll you need to survive them.
Expected profit
2,500 bb
100,000 hands at 2.5 bb/100
70% of players end between
-106 bb … 5,007 bb
95% of players end between
-2,854 bb … 7,289 bb
Chance of losing money
15.8%
after the full sample, per simulation
Best simulated run
11,894 bb
Worst simulated run
-6,447 bb
Median max downswing
19.5 buy-ins
1,953 bb
Bad-luck (95th pct) downswing
38.7 buy-ins
3,872 bb
10 buy-ins
98%
20 buy-ins
47%
30 buy-ins
15%
50 buy-ins
1%
A downswing is measured peak-to-trough within the sample. 1 buy-in = 100 big blinds.
9.60%
Probability of ever losing the whole bankroll at this win rate, playing these stakes forever.
Bankroll for 1% risk of ruin59 buy-ins
Bankroll for 5% risk of ruin38 buy-ins
Bankroll for 10% risk of ruin29 buy-ins
Enter your win rate and standard deviation in big blinds per 100 hands, plus the number of hands you plan to play. The calculator instantly simulates 1,000 independent runs of that sample and shows you 20 of them, along with the 70% and 95% confidence envelopes around your expected value. Toggle to dollars to see everything converted at your stake's big blind size.
The numbers most players find eye-opening are in the panels below the chart: the median maximum downswing (half of all runs had a worse one), the probability of hitting a 20 or 30 buy-in downswing inside your sample, and your risk of ruin at your current bankroll.
A 2.5 bb/100 winner over 100,000 hands still loses money in roughly one out of six simulated runs. That's not a leak — it's math. Understanding the spread of outcomes keeps you from torching a bankroll at stakes you technically beat, and from making tilt-driven conclusions about your game after a bad month. If you don't know your true win rate and standard deviation, the calculator is guessing — Stacker measures both automatically from your logged sessions.
Variance is the statistical measure of how far your short-term results swing around your true win rate. Even a solid winner with a 5 bb/100 win rate will regularly experience breakeven stretches of tens of thousands of hands and downswings of 20+ buy-ins — not because they play badly, but because of the natural spread of outcomes.
Typical values are 60–70 bb/100 for full-ring no-limit hold'em, 80–100 bb/100 for 6-max, and 110–140 bb/100 for heads-up or very aggressive styles. Live games tend to run slightly lower per 100 hands. If you track your sessions in Stacker, the app calculates your actual standard deviation for you.
Risk of ruin is the probability that you eventually lose your entire bankroll despite being a winning player, if you keep playing the same stakes indefinitely. It depends only on your win rate, standard deviation, and bankroll size. The classic formula is RoR = e^(−2 × win rate × bankroll ÷ variance).
Each time the inputs change, the calculator runs 1,000 independent Monte Carlo simulations of your full sample (up to 10 million hands) and displays 20 of them on the chart. The downswing and probability numbers are computed across all 1,000 runs.
Your results per 100 hands stay just as swingy, but your cumulative return converges toward your true win rate as the sample grows — the confidence cone in the chart narrows relative to expected profit. This is why win rates measured over fewer than ~50,000 hands are unreliable.
Stacker calculates your real win rate, standard deviation, and bankroll automatically from your sessions — the numbers this calculator asks you to guess.