Poker Downswing Probability Calculator

Calculate the likelihood of experiencing a specific downswing size based on your win rate, variance, and sample size to prepare for inevitable variance.

Formula:P(Result ≤ -X) using normal distribution

Your expected win rate in big blinds per 100 hands

Typical: 70-90 for cash, 100-150 for tournaments

Sample size to analyze

Downswing amount in big blinds (e.g., 1000 = 10 BI)

For converting to currency values

Try These Examples

Quick-start with common scenarios

Bankroll Simulator

Monte Carlo simulation with 1,000 iterations

$

Your initial capital

%

Your expected advantage

%

Percentage of bankroll per bet

Total bets to simulate

Understanding Poker Downswings

A downswing is a period where your results are significantly below expectation. They're mathematically inevitable in poker and happen to every player.

The Math: We use the normal distribution to calculate probability. Your results follow a bell curve centered on your expected value, with spread determined by standard deviation.

Sample Size Matters: In small samples (under 30,000 hands), even large downswings are normal. A 3 BB/100 winner has about a 30% chance of being down after 20,000 hands.

Mental Game: Understanding that downswings are expected helps maintain emotional stability. When you know a 10-buyin downswing has a 15% chance of occurring, it's easier to stay focused on making good decisions rather than results.

Practical Advice: Always have a bankroll that can withstand a 20-30 buyin downswing. If you can't handle the swings at your stakes, move down.

Frequently Asked Questions

How likely is a 10 buyin downswing?

For a typical 5 BB/100 winner with 80 BB/100 SD, a 10 buyin downswing will happen roughly once every 50,000-100,000 hands. Even excellent players averaging $25/hour experience 1000 BB ($5,000 at $2/$5) downswings.

Why do I keep having downswings?

Downswings are a mathematical certainty in poker, not a sign of bad play. A 3 BB/100 winner has about a 40% chance of being down after 10,000 hands. Only after 100,000+ hands do results become statistically meaningful.

How long do downswings last?

Downswing duration varies wildly. A 20 buyin downswing for a 5 BB/100 winner might last 30,000-50,000 hands (300-500 hours of play). Tournament players can have year-long downswings due to extreme variance.

Should I move down during a downswing?

If your bankroll drops below 20 buyins for your current stake, yes. This protects your bankroll and reduces stress. Many pros use a 'stop-loss' rule - move down after losing 3-5 buyins in a session.

How do I mentally handle downswings?

Focus on making good decisions, not results. Track your decisions separately from outcomes. Take breaks when frustrated. Remember that downswings are part of the game and mathematically expected.