Net versus for-one
A 5:1 payout usually means five units of profit plus return of stake. A five-for-one return may include the stake and provide only four units of profit.
Ambiguous wording can create a full-unit calculation error.
Mutually exclusive categories
Order hand categories so each result receives one payout. A straight flush should not also be counted as a flush and straight unless the rules deliberately pay multiple awards.
Category probabilities must sum to the total winning probability.
Frequent small changes
Reducing a common payout can matter more than increasing a spectacular rare prize. Video-poker full-house and flush values illustrate this effect.
Compare contribution as probability multiplied by payout change.
Caps and qualification
Maximum awards, progressive eligibility, required credits, and dealer qualification can alter effective return.
A calculator should expose these assumptions rather than hide them behind one number.
Working checklist
- Clarify net payout
- List exclusive categories
- Use matching probabilities
- Include caps and eligibility
- Label deck and rule model
This lesson explains general gambling mathematics and uses rounded examples. A game-specific figure applies only to the rules, pay table, strategy, and denominator stated with it. Last reviewed September 20, 2026.