For a target with per-box probability p across n independent boxes, the chance of pulling it at least once is P = 1 − (1 − p)n.
Secret odds calculator
What 1 in 144 actually means
If every box has the same independent 1/144 chance, opening 144 boxes gives about a 63.3% chance of at least one hit — not 100%. The expected number of hits is one, but an expected value is an average across many repeated experiments, not a schedule for your shelf.
| Boxes | Chance of ≥1 secret | Chance of none |
|---|---|---|
| 1 | 0.7% | 99.3% |
| 12 | 8.0% | 92.0% |
| 24 | 15.4% | 84.6% |
| 72 | 39.4% | 60.6% |
| 144 | 63.3% | 36.7% |
When this formula is the wrong model
The direct formula assumes repeated independent draws with the same probability. A sealed case may use a packing rule, a guaranteed regular assortment, or a secret that replaces one regular. Those boxes are not necessarily independent of one another. Use the manufacturer’s exact case rules when they are published; do not convert a single-box odds label into a case guarantee.
Official odds, patterns and community estimates
BoxDex keeps the number and its confidence separate:
- Official — explicitly stated by the manufacturer or on the product packaging.
- Pattern — inferred from a common format, but not confirmed for that exact series.
- Community — a collector estimate when no official probability is available.
The calculator can use any of them, but the label should travel with the result. More decimal places do not make an estimated input more authoritative.
Direct odds and full-set math are different
The equation above answers “what is my chance of this one target in n boxes?” Completing a whole set with duplicates is a different problem. The BoxDex development build simulates 1,000 collectors drawing from the series distribution and reports mean, median and p90 boxes, with secrets included or excluded. That is an estimate, not a guarantee or spending recommendation.
Use the result with the collection record
Probability describes uncertainty. Your album describes what is already true. Read the result beside the missing list and duplicate count — then make your own purchasing decision. See the collection tracking guide for a clean data structure.
The same calculation, in the app.
BoxDex’s development build supports catalog odds and custom manual input. The app is not yet publicly available.
Join the waitlist