Core idea
If a deck has 40 cards and you play 3 copies of a card, probability math can estimate the chance of seeing at least one copy in your opening hand.
Hypergeometric method
Card draw probability is commonly modeled without replacement because drawn cards leave the deck.
Deck testing use
Use probability to compare ratios, then test hands to account for sequencing, bricks, and matchups.
Frequently Asked Questions
What opening hand size should I use?
Use 5 cards for going first and 6 after the first draw when checking going second ideas.
Does probability guarantee consistency?
No. It estimates long-run chances, not individual games.