📅 Calendar Filter Analysis
Find patterns by day · month · date · year range — Answer "Do Tuesday draws favor X?" / "Same date across years?" etc.
😔 No draws match — try adjusting filters
🔥 Most frequent digits in this subset
❄️ Least frequent digits in this subset
What is z-score?
Number indicating how far a digit's count is from expected, in standard deviations
- ➕ High z = appeared more than expected
- ➖ Low z = appeared less than expected
- z ≥ +1.96 or ≤ -1.96 = significant (95% confidence)
📐 Digit sum stats
🧪 Test: Are digits 0-9 equally distributed in this subset?
Chi-square goodness-of-fit test vs uniform distribution
📖 What is Chi-square?
A statistical "ruler" testing whether observed numbers deviate from expected numbers more than random chance can explain.
📊 Calculation steps for this subset:
- มี งวดตรงเงื่อนไข × หลัก/งวด = ตำแหน่งทั้งหมด
- ถ้าเลข 0-9 กระจายเท่ากัน ทุกตัวควรออก = ÷ 10 = ครั้ง (คาดหวัง)
- นับจริงว่าออกกี่ครั้งแล้วเทียบ — สูตร:
χ² = Σ ((observed − expected)² ÷ expected)
📋 Calculation table for this subset
| Digit | Observed (count) | Expected (count) | Diff | χ² part |
|---|---|---|---|---|
| Total (χ²) = | ||||
⚖️ Compare to threshold
Critical value = 16.92 from chi-square distribution table at 95% confidence with df (degrees of freedom) = 9
Why df = 9? We have 10 categories (digits 0-9) minus 1 constraint (the digit counts must sum to total spots) → df = k − 1 = 10 − 1 = 9. This is the "number of truly independent variables" — if you know 9 counts, the 10th is forced by the sum.
Decision:
• χ² greater than 16.92 → deviation from uniform is too large for random chance to explain → statistically significant
• χ² less than or equal to 16.92 → deviation is within what random chance can produce → no evidence of a real pattern
⚠️ Each draw is independent — past patterns do not predict future draws. For entertainment only.
⚠️ Each draw is independent — past patterns do not predict future draws. For entertainment only.
Analyze Thai lottery by calendar — 30+ years of data
Many believe lottery numbers follow patterns by day-of-week or month. This tool lets you test those beliefs yourself with real data going back to 1995 (~750 draws).
Common result: chi-square test typically fails p = 0.05, meaning digit distribution on any specific day matches the overall distribution — direct evidence that lottery is uniformly random regardless of calendar.