What does 5/2 mean?
Fractional odds of 5/2 describe $5 of profit for each $2 staked on a winning ticket at that price. The original stake is returned too. In a simplified example, a $2 winning bet at exactly 5/2 returns $7 total: $5 profit plus the $2 stake. A losing win bet loses its stake.
| Fractional odds | Decimal odds | Profit | Total return |
|---|---|---|---|
| 1/1 | 2.00 | $2 | $4 |
| 5/2 | 3.50 | $5 | $7 |
| 3/1 | 4.00 | $6 | $8 |
| 10/1 | 11.00 | $20 | $22 |
Convert the price to a probability
Decimal odds equal one plus the fractional profit multiple. Raw implied probability is 1 divided by decimal odds. At 3/1, decimal odds are 4.00 and the raw break-even probability is 25%. That is a price calculation, not proof that the horse has a 25% chance.
When comparing a full field, the implied shares may add to more than 100%. GAMELIN normalizes across active runners for its market comparison. Raw break-even probability and normalized market share answer different questions; neither is automatically the model's own estimate.
A displayed price is not a locked price
In a pari-mutuel pool, prices can change as additional money arrives. These arithmetic examples do not guarantee the settled payout, which can also depend on official rules, breakage, dead heats and other adjustments. Consult the official result for the paid amount.
Use the price without overstating it
Try the odds calculator for conversions. To compare a price with an assumed chance of winning, use the separate fair-odds calculator. A shorter-priced favorite may be more likely to win, but that does not automatically make it a better purchase.
Sources and scope
Official references and GAMELIN's published evidence. Check current track and operator information before acting.