You are playing online and your HUD shows an opponent with a VPIP of 60% and a 3-Bet of 20%. He looks like a maniac. You decide to call his 3-bet light, expecting to dominate his wide range. You lose.
Then you look at the sample size: 30 hands.
In poker, data without context is dangerous. A stat like “3-Bet %” requires hundreds of opportunities to converge to an accurate number. Our Poker Stats Calculator brings scientific rigor to your reads. It calculates the Confidence Interval and Margin of Error for any stat, telling you exactly how much you should trust the numbers on your screen.
Poker Stats Logic
HUD Analytics"How many hands do I need to be sure my VPIP is accurate within ±2%?"
How to Use the Calculator
This tool helps you distinguish between a solid read and statistical noise. It features two modes:
1. Analyzer Mode (Is this stat reliable?)
Use this when you see a specific number in your HUD and want to check its accuracy.
- Enter Hands / Opportunities: For VPIP, this is total hands played. For specific stats like “Fold to C-Bet,” enter the number of times the situation actually occurred.
- Enter Actions Taken: How many times did they voluntarily put money in the pot (VPIP) or raise?
- Read the Result: The tool gives you a “Confidence Range.” If the range is 20% to 50%, you know you cannot pinpoint their playstyle yet.
2. Sample Size Mode (How many hands do I need?)
Use this to plan your grinding or database analysis.
- Estimated Stat: Enter the rough percentage you expect (e.g., 25% for VPIP).
- Desired Margin of Error: How precise do you need to be? (e.g., ±2%).
- Result: The tool calculates the mathematical “Long Run” required to achieve that precision.
Related Tools: Once you have reliable stats, use the Hand vs Range Calculator to exploit your opponent’s frequencies. If you are worried about the variance in your own win rate, check the Poker Variance Calculator.
Real-World Examples: The “Sample Size” Trap
Why do pros say you need 10,000 hands to know your win rate? Here is the math behind the madness.
Example 1: The “Fake” Aggressor
You have 50 hands on a villain. His 3-Bet is 12% (High). Is he aggressive?
- The Math: 12% over 50 hands means he 3-bet roughly 6 times.
- The Confidence Interval: The calculator shows a range of 3% to 21%.
- The Reality: He might be a maniac (21%), or he might be a complete Nit (3%) who just happened to get Kings and Aces twice in two orbits. You cannot trust this stat yet.
Example 2: VPIP Convergence
You have 1,000 hands on a Regular. His VPIP is 22%.
- The Math: With 1,000 samples, the margin of error drops significantly (around ±2.5%).
- The Reality: You can be 95% sure his true VPIP is between 19.5% and 24.5%. This is a reliable read. You can safely label him as a “Tight Aggressive” (TAG) player.
Example 3: Rare Events (River Call Efficiency)
Stats that happen deeply in the hand (Turn/River) require massive samples. To get a reliable “Fold to River Check-Raise” stat, you might need 20,000+ total hands, because the specific situation (River -> Check -> Raise) happens so rarely.
Frequently Asked Questions (FAQ)
What is VPIP and PFR?
VPIP (Voluntarily Put Money In Pot) measures how often a player plays a hand. PFR (Pre-Flop Raise) measures how often they enter the pot with a raise. A large gap between VPIP and PFR (e.g., 40/10) usually indicates a passive, recreational player (“Fish”).
What is a “Confidence Interval”?
A Confidence Interval (usually 95%) is a range of values that likely contains the true percentage. If your HUD says 50% with a margin of error of ±10%, it means the player’s true frequency is likely between 40% and 60%.
How many hands do I need for reliable 3-Bet stats?
Because you don’t have an opportunity to 3-bet every hand (someone must raise before you), “Opportunities” accumulate slower than total hands. Generally, you need at least 500 to 1,000 total hands on an opponent to get a rough idea of their 3-bet frequency.