Pull-rate calculator

This tool converts a per-pack hit probability into the chance of seeing at least one hit and the expected number of hits. It is not a bankroll, recovery, or profit calculator. For live Rip Station pack prices, estimated card-value EV, and buyback arithmetic, use the live EV page.

Calculator

Decimal chance per pack. 0.01 means 1%.

Whole number of packs or draws.

Chance of at least one hit: 63.4%

Expected hits: 1

These figures are probabilities under the selected model, not a number of packs that guarantees a hit and not a profit forecast.

Methodology

For independent trials with p = 0.01 and n = 100, the chance of at least one hit is 63.4% and the expected number of hits is 1.

Independent identical trials assume each pack has the same probability p of containing the target, and that one pack does not change the next. Under that model the chance of at least one hit in n packs is 1 − (1 − p)^n, computed with log1p and expm1 so small p stays numerically stable. Expected hits are n × p. Boundaries: p = 0 yields 0%; p = 1 with n > 0 yields 100%; n = 0 yields 0 hits and 0%.

Retail sealed-pack rates often come from a finite print run, so independence can be a rough approximation rather than a physical fact. Label that assumption when you reuse a published rate. Changing the inputs here never changes any published source rate; this page does not ship set pull-rate tables.

Rip Station machines draw from current vault inventory. Pulls and restocks change the pool, so the independent formula is not a description of a live machine. Finite-pool mode is available only when you enter verified N (pool size) and K (target count). Then the chance of at least one hit in n draws without replacement is 1 − C(N − K, n) / C(N, n), implemented as a product that avoids factorial overflow. Draws cannot exceed N.

Expected hits are an average across many hypothetical repeats, not a count you are owed. More packs raise both the chance of a hit and the amount spent. Use current machine EV when you want pack price and estimated value, not this probability tool.