📖 Overview

Use this calculator to evaluate deck consistency and opening hand reliability for board game card systems.

🧪 Example Scenarios

Use these default and higher-pressure example inputs to explore how sensitive this calculator is before using your real numbers.

InputBase CaseHigher Pressure Case
Desired Cards In Deck89.2
Total Deck Size6069
Cards Drawn1011.5
Desired Hits Needed11.15

⚙️ How It Works

Uses a hypergeometric model to estimate the probability of drawing at least a target number of desired cards without replacement.

The Formula

P(X ≥ k) = Σ [ C(K,i) × C(N−K, n−i) ] / C(N,n), for i = k..min(K,n)
NTotal deck size
KDesired cards in deck
nCards drawn
kMinimum desired hits needed
💡This is the standard card-draw probability model used for TCGs and deck builders when cards are drawn without replacement.

Quick Reference

Deck setupDraw targetProbability
8 targets in 60-card deckAt least 1 in 7 draws~65.34%
8 targets in 60-card deckAt least 2 in 10 draws~24.19%
12 targets in 40-card deckAt least 1 in 5 draws~85.10%
6 targets in 50-card deckAt least 1 in 6 draws~55.73%

When To Use This

  • Use this tool when you need a fast decision during active planning or execution.
  • Use this before committing money, time, or tradeoffs that are hard to reverse.
  • Use this to compare options using the same assumptions across scenarios.

Edge Cases To Watch

  • Results can be misleading if key inputs are missing, stale, or unrealistic.
  • Very small or very large values may amplify rounding effects and interpretation risk.
  • If assumptions change mid-decision, recalculate before acting.

Practical Tips

💡 Lower deck size or higher target-card count strongly increases hit odds.
💡 Use this to compare consistency before finalizing deck lists.
💡 Run a best-case, base-case, and worst-case scenario before deciding.
💡 Use recent real values, not ideal assumptions, for better accuracy.

Frequently Asked Questions

❓ Why not use simple percentage?

Simple percentage ignores no-replacement effects and is less accurate for card draws.

❓ Can required hits exceed cards drawn?

No, required hits must be less than or equal to cards drawn.