Moneyline edge when the favourite is short
A short moneyline favourite can still be a bad price. How to turn odds like 1.21 into a chance, compare it with your own, and see the edge go negative.
On this page
A short favourite on the moneyline is only worth backing if you think it wins more often than the price already says. At 1.21 the price says 82.6%. If your number is lower, the edge is negative however likely the team is to win. That is the whole idea, and the rest is the working.
Turning a moneyline into a chance
Decimal odds convert straight to a chance: divide 1 by the price.
| Price | Implied chance |
|---|---|
| 1.21 | 82.6% |
| 1.50 | 66.7% |
| 1.91 | 52.4% |
| 2.56 | 39.1% |
In American odds 1.21 is about -476. Same bet, different notation, as we cover in why odds formats do not change the bet.
The edge on a real short favourite
Our Desk had Dallas against Tampa Bay on 9 October. Here is the card.
| Side | Our chance | Fair price | Best price seen | Edge |
|---|---|---|---|---|
| Dallas Cowboys | 57.0% | 1.75 | 1.21, Betfair | -25.6 pts |
We rated Dallas more likely than not to win. The market rated them far more likely. The gap, minus 25.6 points, is how much the price overstated Dallas on our number. Dallas lost. That does not prove us right; one game proves nothing. It does show what a negative edge on a favourite looks like.
Where a short favourite can be value
The other direction exists too. Today's Desk has San Francisco at 52.2% against a best price of 2.56, a positive edge of 13.2 points, as covered in Seahawks v 49ers prediction: our chances. The 49ers are an underdog in that market. Edges sit wherever our number and the price disagree, and that is as often on an outsider as on a favourite.
A short favourite becomes value only when you have a specific reason to think the market is too low: a late injury to the other side it has not priced, for instance. Without that reason, short prices carry the bookmaker's margin on a result that pays very little.
What this does not tell you
It does not tell you favourites are bad bets. Many win, and plenty are priced fairly. It does not say our 57.0% on Dallas was right either. It only shows how to check a short price against a number of your own.
Common questions
What does a short favourite mean on the moneyline?
A team priced to win at low odds, such as 1.21 in decimal (about -476 in American odds). The bookmaker is saying they win around 83 times in 100.
Can backing a short favourite have a positive edge?
Yes, but only if your own chance is higher than the one the price implies. At 1.21 you need more than 82.6% just to break even before margin.
What happened with the Cowboys at 1.21?
We rated Dallas 57.0% against Tampa Bay, far below the 82.6% the price implied, so our edge was minus 25.6 points. Dallas lost.