Why a 20% contribution game costs five times as much
You hold 100 SC with a 2x requirement, but the game you want to play contributes only 20% toward it. How much does that change the cost?
Inputs
| Input | Value | Unit |
|---|---|---|
| Starting Sweeps Coins | 100 | SC |
| Playthrough multiplier | 2 | x |
| Game contribution | 20 | % |
| Assumed RTP | 96 | % |
Working
- The requirement itself is unchanged: 100 x 2 = 200 SC of credited wagering.
- But only 20% of each coin staked is credited. To generate 200 SC of credit you must stake 200 / 0.2 = 1,000 SC.
- The house edge applies to what you actually stake, not to what gets credited. The expected loss is 1,000 x 0.04 = 40 SC, five times what the same requirement would cost at full contribution.
- The break-even multiplier falls in the same proportion: 0.2 / 0.04 = 5x rather than 25x. At 20% contribution, a requirement above 5x is expected to consume the whole balance.
- This is the single largest effect on this site, and it is the one most often left out of a package comparison. Contribution does not change the odds of the game. It changes how many times you have to face those odds.
Result
| Output | Value |
|---|---|
| Requirement (credited) | 200.00 SC |
| Must actually stake | 1,000.00 SC |
| Expected loss | 40.00 SC |
| Expected balance after | 60.00 SC |
| Break-even multiplier | 5x |
Takeaway
Contribution divides. Halving the contribution doubles what a requirement costs, and dropping it to 20% multiplies the cost by five.
The formula behind it
h = 1 − r
T = (B × m) ÷ c
E[loss] = T × h
E[balance] = B − (T × h)
m* = c ÷ h (the multiplier at which the expected balance reaches zero)
Assumptions
- Every coin staked is staked at the same assumed RTP r. Switching games changes r and therefore changes the result.
- With predetermined turnover T held fixed, expected value is linear in T. This follows from the linearity of expectation and holds regardless of how that wagering is split into individual bets — bet sizing does not change the expected total loss when T is unchanged, only how the results spread out around it.
- The full requirement is actually staked. The model does not stop when the balance runs out, which is why it is only valid while the expected balance stays above zero.
- No jackpot contribution, side bet, rake, or promotional credit sits outside the stated RTP.
Limitations
- This is an average over an extremely large number of repetitions, not a forecast of one session. Half of all real sessions finish below the average, and for a high-volatility game most finish well below it while a few finish far above.
- Because the model keeps staking after a real balance would be gone, B − T×h is usually a lower bound on the true expected balance rather than an exact figure. The published simulator can overshoot required turnover T by up to one stake on the last bet, so that bound is not a theorem under the simulator. Once the result reaches zero the model stops reporting a number, because a balance cannot go negative and a false precision there would be misleading.
- It cannot produce the probability of completing a requirement. That depends on the game’s full payout distribution and bet size, neither of which is an input here.
- Published RTP is a long-run property of a game’s design. It does not describe, predict, or guarantee any individual result.
This is a theoretical calculation, not a prediction. It describes an average over a very large number of repetitions and says nothing about what will happen in any particular session.
Run these numbers yourself · All worked examples · Methodology