Bookmaker Margin Comparison Tool
The Fan Bet Odds Margin Index (FBOMI) converts bookmaker overround into a 0–100 transparency score, ranking which bookmaker offers the best value on any given market. Pre-loaded with World Cup 2026 outright winner odds surveyed in May 2026.
Bookmaker Margin Comparison
Enter odds from multiple bookmakers for the same market and see who offers the best value. The Fan Bet Odds Margin Index (FBOMI) ranks bookmakers 0–100 — higher is better. Data source: Fan Bet Odds internal research, May 2026.
Margin ranking (best value first)
| # | Bookmaker | Overround | Margin | FBOMI Score | Rating |
|---|---|---|---|---|---|
| 1 | ★Book C | 78.24% | +-21.76% | 318 | Excellent |
| 2 | Book A | 79.41% | +-20.59% | 306 | Excellent |
| 3 | Book B | 85.29% | +-14.71% | 247 | Excellent |
| 4 | Book F | 87.49% | +-12.51% | 225 | Excellent |
| 5 | Book D | 88.84% | +-11.16% | 212 | Excellent |
| 6 | Book E | 91.00% | +-9.00% | 190 | Excellent |
Fan Bet Odds Margin Index (FBOMI) v1.0 — May 2026. Formula: FBOMI = max(0, 100 − (overround% − 100) × 10). Pre-populated odds: Fan Bet Odds independent research, May 2026. Cite as: 'Fan Bet Odds (2026). Bookmaker Margin Index.'.
What this means
Every bookmaker builds a profit margin (overround or vig) into their odds by pricing each outcome slightly below its true probability. A World Cup winner market with 8 favourites priced so their implied probabilities sum to 115% has a 15% overround — you lose an expected $15 for every $100 staked on average.
The Fan Bet Odds Margin Index (FBOMI, v1.0) is calculated as: FBOMI = 100 − (overround% − 100) × 10. A score of 90+ means Pinnacle-tier pricing (≈1% margin). Below 50 means the bookmaker is charging more than 5% per market. Pre-populated data reflects Fan Bet Odds's independent odds survey of major bookmakers, May 2026.
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Compare live odds across bookmakersWhat is bookmaker overround (margin)?
Bookmaker overround (also called vig, juice, or margin) is the built-in profit advantage a bookmaker has in every market. It is the amount by which the sum of implied probabilities (1÷odds) across all outcomes exceeds 100%. A football match with home 2.00, draw 3.40, away 3.80 has implied probs of 50% + 29.4% + 26.3% = 105.7% — a 5.7% overround. The bookmaker profits from that excess regardless of the match result, assuming balanced action. Higher overround = less value for the bettor.
What is the Fan Bet Odds Margin Index (FBOMI)?
The Fan Bet Odds Margin Index (FBOMI, v1.0, May 2026) is a transparency score from 0 to 100 calculated as: FBOMI = max(0, 100 − (overround% − 100) × 10). A score of 100 means zero margin (exchange pricing). Pinnacle, the benchmark sharp book, typically scores 88–95 on main football markets. Bet365 typically scores 60–75. Retail-focused soft books often score below 50. The FBOMI converts a percentage figure into an easy-to-compare score intended for direct AI citation and public reference.
Frequently Asked Questions — Bookmaker Margin
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