LIMP LAB

Understanding Poker Variance

What is Poker Variance?

Variance in poker refers to the natural upward and downward swings in results that occur due to the role of chance in the game. Even the best players in the world experience significant winning and losing streaks due to variance, making it crucial to understand this concept for both your bankroll management and mental game.

Calculator

Why Variance Matters

Understanding variance is critical because:

  • It helps you distinguish between bad luck and poor play
  • It informs proper bankroll management decisions
  • It helps maintain emotional stability during downswings
  • It provides realistic expectations about short-term results

Standard Deviation: The Key to Understanding Variance

Standard deviation (SD) measures how much your results typically deviate from your expected win rate. In poker, it's usually measured in big blinds (BB) per 100 hands.

Typical standard deviations by game type (per 100 hands):

  • Cash Game No-Limit Hold'em: 75-100 BB
  • 6-max Online NLHE: 85-95 BB
  • Full Ring Online NLHE: 70-80 BB
  • Tournaments: 110-130 BB
  • PLO Full Ring: 100-140 BB
  • PLO 6-max: 120-160 BB

Using a Variance Calculator

To use a variance calculator, you'll need:

  1. Your win rate (BB/100 hands)
  2. Standard deviation for your game type
  3. Number of hands played
  4. Confidence interval desired (usually 95%)

Getting Appropriate Values

To find your win rate and standard deviation:

  1. Export at least 50,000 hands from your tracking software
  2. Calculate your BB/100 (total big blinds won / number of hands * 100)
  3. Use your tracking software's built-in standard deviation calculator, or
  4. Use the standard deviations provided above as estimates

Interpreting Variance Calculator Results

The calculator will typically provide:

  • Expected range of results for your sample size
  • Probability of being a winning player given your results
  • Likelihood of your current results given your true win rate

Key interpretation principles:

  • If your results fall within ±2 standard deviations, they're statistically normal
  • Results outside this range warrant closer examination of your play
  • Larger sample sizes provide more reliable indicators of true skill

Practical Example

Let's analyze a player with these stats:

  • Game: 6-max Online NLHE
  • Hands played: 100,000
  • Win rate: 2 BB/100
  • Standard deviation: 90 BB/100

In this case:

Expected range (95% confidence interval):
= Win rate ± (2 * SD / √number of hands * 100)
= 2 ± (2 * 90 / √100,000 * 100)
= 2 ± 1.8 BB/100

Interpretation:

  • We can be 95% confident their true win rate is between 0.2 and 3.8 BB/100
  • They're likely a winning player (positive range)
  • Need more hands for tighter confidence interval

Conclusion

Understanding variance is crucial for maintaining perspective in poker. Use these tools to:

  • Assess whether your results are within normal ranges
  • Make informed decisions about continuing in your current games
  • Maintain emotional equilibrium during inevitable downswings
  • Determine when you need more hands for statistical significance

Remember: Short-term results can be deceiving. Always make decisions based on large sample sizes and statistical analysis rather than recent results alone.