The same game, two RTP builds, side by side in pounds. This is the difference operators are not required to show you.
Worked example. £2 a spin, 600 spins an hour for 10 hours is 6,000 spins and £12,000 staked.
| Configuration | Expected loss |
|---|---|
| 96.21% | −£455 |
| 92.50% | −£900 |
The lower build costs £445 more over the same play.
How this is calculated
Expected loss is arithmetic, not a simulation: total staked multiplied by the house edge, which is one minus the RTP. Every £2 spin at a 96.21% build returns £1.92 on average, and the shortfall compounds with turnover rather than with how long you sit there.
The other columns are simulated. Winning spins pay a log-normal multiplier, fitted so the model reproduces both the RTP you entered and the standard deviation of the volatility class you picked; two thousand sessions of your chosen length are then run in your browser and the percentiles read off the results. We tried the textbook shortcut of assuming a bell curve and dropped it: slot returns stay heavily skewed even after thousands of spins, and the shortcut moved the typical session about £250 in the player's favour.
The number that matters is the gap between the two rows. Luck moves both rows together; the configuration moves one of them permanently.
If you joined GamStop because gambling was becoming a problem, this page is not for you. GamStop exists because it works. Free, confidential help is available from GamCare on 0808 8020 133, and from BeGambleAware.