Core calculation
Cash stake = declared fraction * eligible bankroll
In an illustrative record, the eligible bankroll is GBP 400 and the declared fraction is 1%:
Stake 1 = 0.01 * 400 = GBP 4.00
After that stake loses, the bankroll is GBP 396. If the rule recalculates after each settled bet:
Stake 2 = 0.01 * 396 = GBP 3.96
If stake 2 wins at decimal odds 2.00, its net profit is GBP 3.96 and the bankroll becomes GBP 399.96.
These values demonstrate arithmetic only. They do not recommend 1% or imply that either bet had positive expectation.
Define the denominator
The percentage is meaningless without the bankroll definition. State whether the denominator includes:
- cash held outside operators;
- withdrawable operator balances;
- unsettled back stakes;
- exchange lay liability;
- bonuses or non-withdrawable credit;
- deposits added during the period.
A conservative record excludes already committed exposure from available cash and keeps household funds outside the calculation.
Choose a recalculation policy
| Policy | Benefit | Risk or ambiguity |
|---|---|---|
| After every settlement | Tracks current bankroll closely | Settlement order can change stakes |
| Daily snapshot | Easier reproducibility | Intraday bankroll can differ |
| Weekly snapshot | Stable cash stakes | Can lag a large drawdown |
| High-water mark | Avoids automatic increases after a dip | Stake may not shrink with current capacity |
There is no universal best reset rule. Choose one before the review period and preserve each snapshot.
Percentage staking is not Kelly
Kelly staking uses probability and payoff assumptions to maximize expected logarithmic growth under its model. A constant percentage selected without those inputs is simply a sizing convention. Even where Kelly inputs exist, sports-wagering research shows that uncertainty in the estimated win probability can materially alter suggested fractions (Chu, Wu and Swartz).
If the estimated expectation is negative, choosing a smaller percentage reduces cash exposure but does not make the decision positive EV.
Control portfolio exposure
In an illustrative no-offset case, ten simultaneous 1% stakes expose about 10% of the pre-bet bankroll; dependence can concentrate the risk further. Calculate total open stake and maximum loss by match, team, market, and shared outcome rather than applying the per-bet percentage in isolation.
Reconcile simultaneous decisions
In an illustrative simultaneous-decision check, a GBP 400 snapshot produces three 1% stakes before any settle. Each is GBP 4, so nominal open stake is GBP 12. It is incorrect to calculate the second from GBP 396 and the third from GBP 392 when the cash has merely become unsettled under a rule based on settled bankroll. Define whether committed cash is deducted from the eligible denominator.
Preserve the snapshot ID on every decision. When bets settle out of order, the recorded stake remains tied to the original snapshot. This avoids a backtest in which historical settlement order changes stake size. Add a separate maximum-open-exposure rule so a burst of simultaneous one-percent signals cannot bypass the intended period budget.
Next step
Use One Percent Rule Betting for the next part of this topic.
Continue learning
- Next guide: Separate Betting Bankrolls
- Related guide: Stake Sizing Across Bet Types
Assumptions and limitations
The worked path assumes sequential settlement, no commission, and decimal odds 2.00 on the second bet. Real balances can include pending settlement, rejected stakes, partial cash-outs, and currency effects. The declared percentage is not an affordability assessment or evidence of model accuracy.
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