Method
Formulas and assumptions
Everything the instruments compute, in one place.
The formulas
- Spins
- spins per minute × minutes
- Turnover
- spins × bet per spin
- Expected cost
- turnover × (1 − return figure)
- Expected cost per minute
- spins per minute × bet × (1 − return figure)
- Net result
- money at the end − money at the start
- Spread (invented game)
- paying spins K ~ Binomial(n, 0.05); net result = bet × (18K − n); the band runs from the 5th to the 95th percentile of K
Assumptions
- Every spin costs the same bet.
- The return figure applies to every dollar of turnover, as a long-run average.
- The pace you enter is held constant for the whole session.
- Defaults and the spread game are invented examples, not measurements.
How the numbers are checked
The worked examples on each page are calculated when the site is built. The same formulas run in your browser for the calculators, and the build compares the two on several sets of inputs; if they disagree, the site is not published.