Finding a value bet is only half the challenge. Once you believe you have an edge over the bookmaker, the next question is just as important:
How much should you stake?
Bet too little and your edge has little impact on your long-term profits. Bet too much and even a profitable strategy can lead to large losses or even bankrupt your bankroll.
Successful betting is therefore a combination of finding value and managing your stakes wisely.
Your edge is the difference between your estimated probability and the bookmaker's implied probability.
The formula is:
Edge = Your Probability − Implied Probability
For example:
Your edge is:
0.55 − 0.50 = 0.05 (5%)
This means you expect to earn an average profit of approximately £0.05 for every £1 staked over the long run.
Your expected earnings depend on two factors:
The relationship is simple:
Expected Profit = Total Turnover × Average Edge
Suppose you:
Your annual turnover would be:
£500 × 40 = £20,000
If your average edge is 3%:
£20,000 × 0.03 = £600 expected annual profit
This example illustrates an important principle:
Increasing your edge or increasing your turnover can increase your expected profits. Increasing your stakes without a genuine edge simply increases your expected losses.
One of the best-known staking methods is the Kelly Criterion.
The Kelly Criterion calculates the mathematically optimal fraction of your bankroll to stake when you have a positive expected value.
The basic formula is:
Kelly Fraction = Edge ÷ (Decimal Odds − 1)
Example:
Calculation:
0.05 ÷ (2.50 − 1) = 0.05 ÷ 1.50 = 0.0333
This means the full Kelly recommendation is to stake approximately 3.3% of your bankroll.
The Kelly Criterion will be covered in much greater detail in the Staking Strategies section.
Having a positive edge does not guarantee short-term success.
Even excellent value bets lose regularly because sport contains unavoidable randomness.
If you stake too much on each bet, a normal losing streak can quickly deplete your bankroll before your long-term advantage has time to materialise.
The Kelly Criterion identifies the largest mathematically efficient stake. Betting significantly more than this increases risk much faster than it increases expected return.
For this reason, many experienced bettors use Half Kelly or even Quarter Kelly staking to reduce volatility while still benefiting from their edge.
Many new bettors believe that confidence should determine stake size.
Professional bettors take a different approach.
Rather than making occasional large bets on matches they "feel certain" about, they consistently apply disciplined stakes whenever they identify a measurable edge.
Small advantages repeated hundreds of times are far more valuable than chasing a few supposedly guaranteed winners.
Long-term success comes from consistency, patience, and sound bankroll management—not from oversized bets.
Your edge determines your long-term earning potential, while your staking strategy determines whether you survive long enough to realise that edge. Expected profit is simply your total betting turnover multiplied by your average edge. As your edge grows, your expected profits increase, but increasing stake size without a genuine advantage only magnifies losses. The Kelly Criterion provides a mathematical framework for sizing bets, but disciplined staking and consistent application of small positive edges remain the foundation of sustainable betting success.
