Define the rule before the selections
Write one stake amount, start date, end date, included markets, and maximum simultaneous exposure. A rule that changes after losses is not flat staking, even if the average stake later resembles the original amount.
Flat staking controls stake variation. It does not control the number of simultaneous bets, odds distribution, market dependence, or whether a price has positive expected value.
Worked settlement example
The following four one-unit bets are illustrative:
| Bet | Decimal odds | Result | Net units |
|---|---|---|---|
| A | 2.00 | Win | +1.00 |
| B | 1.90 | Loss | -1.00 |
| C | 1.80 | Win | +0.80 |
| D | 2.20 | Loss | -1.00 |
Total stake = 4 units. Net result = 1 - 1 + 0.8 - 1 = -0.2 units. Yield = -0.2 / 4 = -0.05, or -5%.
The two wins do not imply a 50% break-even rate for all prices. Each quote has a different payoff, and expectation requires a probability for every outcome. OpenStax provides the weighted-outcome basis for expected value and variance.
Strengths and limits
| Question | Flat staking effect |
|---|---|
| Does a loss cause a larger next stake? | No, if the rule is followed |
| Does a larger model edge get a larger stake? | No |
| Does stake shrink after bankroll falls? | No, unless the rule is reset |
| Does it prevent too much open exposure? | No; a separate cap is required |
| Does it make a losing price profitable? | No |
Formal ruin analysis depends on the game, bankroll, minimum bet, costs, and stopping conditions; Ferguson demonstrates why those assumptions must be explicit. A small fixed stake can reduce the speed of loss but cannot remove ruin risk from indefinite play with adverse expectation.
Add an exposure rule
If five one-unit bets are open at once, five units are at risk. If the selections depend on the same match or competition outcome, the risk can be more concentrated than the count suggests. Record event, market, and shared outcome drivers, then cap total open exposure under a pre-declared rule.
Reset deliberately
If the bankroll or personal budget changes, end the old staking version and begin a new one with a date and reason. Do not increase the fixed stake because recent bets won, or to recover a drawdown. Do not reduce it only in the published history after seeing losses.
Audit stake drift
Calculate the median, minimum, and maximum accepted cash stake for the period and list every row that differs from the declared flat amount. Separate legitimate causes such as operator partial acceptance or currency rounding from discretionary changes. If a one-unit rule produced stakes from GBP 5 to GBP 20 because the unit value changed, the cash path is not flat and must be reported by version.
Also measure stake as a percentage of the current bankroll after settlement. A fixed GBP 5 stake is 1% of GBP 500 but 2% of GBP 250. This does not automatically make the rule wrong; it reveals that constant cash creates changing proportional exposure. Set a prospective pause or reset boundary rather than discovering one after a drawdown.
Next step
Use Betting Units Explained for the next part of this topic.
Continue learning
- Next guide: Fractional Kelly Betting
- Related guide: Kelly Criterion for Betting
Assumptions and limitations
The example uses complete fixed-odds settlement with no commission and is not a performance forecast. Flat staking is easy to audit, not automatically safe or optimal. The external budget remains controlling, and MoneyHelper's budget process should precede any cash stake.
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