Understanding 'Spil Oddset' - How do I calculate true expected value?

bettingoddsprobabilityexpected valuestrategy

Registration:
02.09.2021
Messages: 50

WildCat Topic author

08.01.2025 03:03

I've been looking at some local betting platforms and I keep running into this term, 'spil oddset,' which I assume relates to the odds or payout structure. I'm having trouble understanding the difference between the implied probability and the actual house edge. When the odds seem really good, how can I tell if the payout is genuinely favorable or if there's a hidden multiplier I'm missing? I've done some basic calculations, but I feel like I'm missing a fundamental concept about how these odds are set to ensure profitability for the house. Any experienced bettors who can walk me through the math would be a massive help.

11 Answers

25.02.2024
Posts: 348

Ghost_C

21.01.2025 18:17

The key concept you need to master is the difference between implied probability and true probability. Implied probability is what the bookmaker *wants* you to think it is, based on their odds. To find the implied probability (P_implied), you simply take 1 / Decimal Odds. This gives you the market's perceived chance of the event happening.

11.01.2021
Posts: 461

PacketSniffer

17.02.2025 18:56

Always calculate the expected value (EV) for every bet. EV = (Probability of Winning * Payout) - (Probability of Losing * Stake). If the EV is negative, walk away.

26.06.2024
Posts: 680

Jude_C

05.04.2025 07:19

To truly understand the house edge, you must calculate the implied probability for all outcomes and compare the sum to 100%. If the sum is less than 100%, the difference is the house's profit margin. For example, if the odds for Team A are 2.00 and Team B are 2.00, the implied probability sum is 50% + 50% = 100%. But if the odds are 1.90 and 2.10, the implied sum is 52.6% + 47.6% = 100.2%. That 0.2% difference is where the bookmaker takes their cut, the vigorish or 'vig'.

25.03.2024
Posts: 1222

Golic_C

28.05.2025 13:47

Check the odds across multiple platforms.

11.02.2024
Posts: 846

IceQueen in response

20.07.2025 15:19

I think your EV calculation is missing the stake in the loss scenario. If you bet $10, and the house edge is 5%, your expected loss per $10 bet is $0.50, regardless of the specific odds, assuming the bookmaker is perfectly set.

31.07.2021
Posts: 520

RedDragon

10.08.2025 15:58

Beyond just the odds, you need to consider variance and bankroll management. Even if you calculate a positive EV, streaks of bad luck can wipe you out. Never bet more than 1-2% of your total bankroll on a single outcome. Understanding your risk tolerance is just as important as understanding the math. The house edge is constant, but your emotional edge can be exploited.

29.12.2023
Posts: 1272

WarzonePro

04.10.2025 16:51

If the odds are too good to be true, they usually are. Be skeptical.

23.02.2024
Posts: 1035

Grandpa_C in response

15.10.2025 07:27

Regarding the implied probability, if the bookmaker sets the odds for a favorite (say, 1.30) and an underdog (say, 8.00), the implied probabilities are 76.9% and 12.5%. The sum is 89.4%. The missing 10.6% is the house edge. This is the fundamental way they guarantee profit.

11.10.2022
Posts: 1251

DigitalNomad

07.02.2026 16:38

A simple example: If you bet $10 on a team with odds of 3.00, your potential payout is $30. If they win, your profit is $20. If they lose, your loss is $10. The odds are favorable only if the true probability is significantly higher than the implied probability.

22.02.2022
Posts: 617

Father_C

11.02.2026 19:41

The ultimate way to minimize the house edge is through arbitrage betting, or 'arbing.' This means finding multiple bookmakers offering odds on all outcomes such that the implied probabilities sum to less than 100%. If you can find an arb opportunity, you are guaranteed a profit regardless of the outcome, as long as the bookmakers haven't changed their lines.

20.08.2023
Posts: 993

DigitalNomad in response

11.04.2026 04:35

Arbing is complex, but mathematically sound.

Want to join the discussion?

To leave a comment, you must log in to the forum.