How to Use the Gacha Result Statistics Analyzer
After pulling in gacha games, you might wonder if the stated probability is accurate. This tool uses binomial distribution statistics to calculate the expected wins, deviation, standard deviation, and z-score from your actual pull results.
A z-score within ยฑ2 is statistically normal (within the 95% confidence interval). A z-score beyond ยฑ3 is statistically unusual โ occurring in less than 0.3% of cases under the stated rate.
Statistical Formulas Used
Expected wins = n ร p | Standard deviation = โ(n ร p ร (1โp)) | Z-score = (actual โ expected) / std
Frequently Asked Questions
Yes, a z-score of -2 occurs in about 2.3% of sessions. It's unlucky, but statistically normal and not evidence of rate manipulation.
Fewer than 30 pulls have high variance and low reliability. For meaningful analysis, we recommend at least 50 pulls โ ideally several hundred.