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Expected value betting: the math behind +EV bets
A value bet, or +EV bet, pays more than the real probability of the outcome warrants. Finding one takes math; cashing in on it takes volume.
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1 Game time
What a value bet is
Every price carries a probability: 1 ÷ decimal odds. At +110 (2.10), it is 47.6%. If you figure the outcome happens more often than that, say 50% of the time, the price pays more than the risk requires. That is a value bet, or a +EV bet.
"Value" does not mean "winning": at a 50% hit rate, this bet loses half the time. The edge exists only on average, and only if the estimate is right. Do not mix it up with arbitrage, which covers every outcome.
2 The stat sheet
Expected value, step by step
Expected value (EV) is what a bet pays on average when it is repeated a very large number of times. Per dollar staked: probability of winning × (decimal odds − 1), minus probability of losing × 1. It boils down to one line.
Per dollar staked EV = probability × decimal odds − 1
Example: $20 at +110 (2.10), on an outcome you put at 50%.
- 1 If the bet wins (50%): 20 × (2.10 − 1) = +$22.
- 2 If it loses (50%): −$20.
- 3 Expected value: 0.50 × 22 − 0.50 × 20 = +$1.
- 4 Per dollar staked: 1 ÷ 20 = +5%. The formula gives the same result: 0.50 × 2.10 − 1 = 0.05.
Five examples: value or not
- -200 (1.50), estimated at 70%
- Implied probability
- 66.7%
- EV per dollar staked
- +5.0%
- Value bet?
- Yes
- -110 (1.91), estimated at 57%
- Implied probability
- 52.4%
- EV per dollar staked
- +8.9%
- Value bet?
- Yes
- +110 (2.10), estimated at 50%
- Implied probability
- 47.6%
- EV per dollar staked
- +5.0%
- Value bet?
- Yes
- +110 (2.10), estimated at 45%
- Implied probability
- 47.6%
- EV per dollar staked
- −5.5%
- Value bet?
- No
- +200 (3.00), estimated at 36%
- Implied probability
- 33.3%
- EV per dollar staked
- +8.0%
- Value bet?
- Yes
3 The box score
Why it takes hundreds of bets
How variance outweighs a 5% edge
Take the +5% bet again. It earns 0.05 units on average (a unit is one stake), but its result swings by 1.05 units around that average (standard deviation: √(0.5 × 0.5) × 2.10). Luck outweighs the edge 21 to 1, and it only fades with volume.
Bettor winning 50% of bets at +110 (2.10) with the same stake each time, a +5% edge. Exact probability of having lost money after n bets.
After 20 bets, this bettor is behind four times out of ten: a return cannot be judged at that volume. The expected profit, meanwhile, grows from 1 unit after 20 bets to 50 units after 1,000.
The bankroll management guide puts numbers on bad runs too: over 100 bets won 55% of the time, five straight losses happen nearly two out of three times (64.7%).
Value is a volume game: the edge only shows after hundreds of bets.
4 The replay
How to estimate a probability
The formula needs a probability that nobody knows. Two ways to get close.
- Start from the market. A sportsbook posting -110 on both sides quotes 52.4% on each, 104.8% in total: the excess is its vig. Divided by the total, each side is back to 50%. Another sportsbook paying +110 on one side then gives the example above.
- Build your own estimate. A model, or the win rate measured in your own record at a given price. The open question is whether it beats the market's.
Either way, it is an estimate. And EV equals the gap between that estimate and the implied probability, times the decimal odds: at 2.10, every point of probability lost takes 2.1 points off the EV. With a 48% chance instead of 50%, +5.0% becomes +0.8%. At 47%, it becomes −1.3%.
The Kelly criterion turns that edge into a stake size, and shows what an overestimated probability costs.
Halftime
Volume takes time
You have the formula. What you need next is time to let it play out: hundreds of bets, at your own pace.
Same bettor, same steady profile. Fan Funded's 3 Step gives 30 days per step and three steps to pass (rules checked on October 3, 2026): the clock caps the volume at 90 bets per step. Prime Sports Funded gives one step and no clock, so the volume builds at the pace of your value bets.
Flat stakes; the math and its assumptions are under the standings.
Prime Sports Funded +35% in one step, no time limit
PROMO2525% off, applied at checkoutCopy
6 Overtime
In a challenge, volume needs time
A challenge caps the stake: at Prime Sports Funded, 5% of the starting bankroll at most per bet. If your 5% edge is real, a bet at 5% earns 0.25% of the bankroll on average (5% × 5%). Reaching +35% then takes about 140 bets on average (35 ÷ 0.25).
Put the same target on a 30-day clock and that is close to five bets a day. With no time limit, you never force a bet to keep up with a calendar. The standings below account for it, loss limit included: the challenge price divided by the chance of passing, on the steady profile.
Steady profile: 55% of bets won at -110 (1.91), 3 bets a day
- 1
Prime Sports Funded Challenge
€114 real cost
72% chance of getting funded. €81.75 with code PROMO25 (€109 without).
See the No. 1 
MySportsFunding Instant Funding
€499 real cost
€499.
Priced in pounds
GetBet Funded Standard plan
£225 real cost
34% chance: 54%, then 63%. 90 bets at most in 30 days. £76 price shown with the operator's 20% discount, no published end date.
Priced in US dollars
Bankroll U Combine
$292 real cost
$245. Based on: Combine only.
Fan Funded 3 Step
$435 real cost
14% chance: 52% per phase, 3 times in a row. 90 bets at most in 30 days. $59.99.
Not ranked: Playvo (bankroll size not published), OddsON (stake limits not published; accounts of 5,000 and up not yet on sale).
Real cost: challenge price ÷ chance of getting funded. Flat stakes, average odds of -110 (1.91).
How we calculate
- Three profiles: 54% of bets won and 2 bets a day; 55% and 3; 57% and 4.
- Each operator is modeled at the stake that gives it the best chance, within its allowed range.
- Time-limited challenge: the number of bets is capped by the profile's pace.
- Several phases: the chances multiply.
- Not simulated: daily loss limits, minimum number of bets, activity targets, consistency rules.
- Bankroll U is taken at its Combine, the lowest real cost among the offers considered for this matchup, on the steady profile. Five levels: not ranked (higher real cost on the steady profile).
- Bankroll U: Combine only, which opens the Rookie level at 10% of profits.
- Fan Funded is taken at its 3 Step, the lowest real cost among the offers considered for this matchup, on the steady profile. 2 Step: not ranked (higher real cost on the steady profile). Blitz: not ranked (too close to call: the gap depends on the exchange rate).
- GetBet Funded: price shown with the operator's 20% discount, no published end date.
- Prime Sports Funded price with code PROMO25.
- Amounts are shown in each operator's own currency, with no conversion. Operators are not ranked across currencies.
- The math holds for these profiles, not for every bettor.
Frequently asked questions
What is EV in betting?
Expected value is what a bet pays on average when it is repeated many times: probability of winning × decimal odds − 1, per dollar staked. At +110 (2.10) with a 50% chance, it is 0.50 × 2.10 − 1 = +0.05, or +5%.
What is a +EV bet, or value bet?
A bet whose odds are higher than the real probability of the outcome warrants, so its expected value is positive. At +110 (2.10) the implied probability is 47.6%. If the outcome happens 50% of the time, the bet is +EV. It still loses half the time.
How do you calculate expected value in betting?
Multiply your estimated probability by the decimal odds and subtract 1. For $20 at +110 with a 50% chance: 0.50 × 22 − 0.50 × 20 = +$1, which is +5% of the stake. A positive result means a value bet, if the probability is right.
How do you estimate a bet's true probability?
Strip the vig from a sportsbook's odds (-110 on both sides is 52.4% each, 104.8% in total, so 50% each once the vig is removed), or use your own model or betting record. Either way it is an estimate: at +110 (2.10), a 2-point error takes 4.2 points off the EV.
How many bets does +EV betting take to pay off?
Hundreds, and more if you want to be sure. For a +5% bet (+110, won 50% of the time), the chance of being behind is 30.9% after 100 bets, 15.2% after 500 and 6.9% after 1,000.
Can you bet for value in a sports prop firm challenge?
Yes, if the challenge leaves you time to build the volume. At 5% of the starting bankroll per bet and a 5% edge, each bet earns 0.25% of the bankroll on average: +35% takes about 140 bets. A 30-day limit means close to five bets a day; with no time limit, the pace is yours.
The final call
Bet for value with no clock
One step at +35%, no time limit: your value bets get the volume they need. The 5,000 challenge costs €81.75 with code PROMO25, down from €109.
Prime Sports Funded No. 1 in our standings
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