Double chance and draw no bet
Two ways to shorten the odds by covering more outcomes, and one arithmetic trap that produces edges of 40 percentage points where none exist. Double chance selections overlap, so they do not normalise to 100%, a fact almost every de-vig calculator online gets wrong.
Double chance backs two of the three outcomes in one bet (home or draw, away or draw, home or away). Draw no bet backs one team and returns your stake if the match is drawn. Both shorten the price in exchange for covering more ground; neither removes the bookmaker margin, and neither is safer once you account for what you are paid.
What does each market cover?
| Market | Wins if | Stake returned if | Loses if |
|---|---|---|---|
| 1X (home or draw) | Home wins or draw | — | Away wins |
| X2 (away or draw) | Away wins or draw | — | Home wins |
| 12 (either team) | Either team wins | — | Draw |
| Draw no bet, home | Home wins | Draw | Away wins |
| Draw no bet, away | Away wins | Draw | Home wins |
Draw no bet is exactly equivalent to backing the home win and hedging the draw at the right size. Bookmakers price it as one bet and charge margin once, which is usually, though not always, cheaper than constructing it yourself.
The trap: double chance does not sum to 100%
De-vigging works by scaling implied probabilities so they sum to 1. That is correct for a market whose outcomes are mutually exclusive and exhaustive: 1X2, over/under, both teams to score. Double chance is neither.
Consider a match with true probabilities: home 45%, draw 28%, away 27%.
| Selection | Covers | True probability |
|---|---|---|
| 1X | home + draw | 73% |
| X2 | draw + away | 55% |
| 12 | home + away | 72% |
| Sum | 200% |
The sum is 200% because every one of the three results is counted in exactly two of the three selections. The correct normalisation target for double chance is 2, not 1.
We hit this on live prices. Normalising a double chance market to 1 implied a 41-percentage-point edge, a number so large it was obviously a bug rather than a discovery. The fix was to give every market family an explicit normalisation target in the taxonomy, checked by test. The failure was silent and plausible-looking, which is exactly what makes it dangerous: a smaller error of the same kind would have looked like a genuine find.
This matters beyond our own code. Free de-vig calculators overwhelmingly assume a target of 1. If you paste double chance prices into one, the output is not slightly wrong; it is wrong by tens of percentage points, in the direction that makes bets look good.
When is either market worth taking?
Both are legitimate bets at the right price. The question is the same as for any market: does your probability estimate beat the de-vigged price? Because these markets are cheaper to be right about, they often carry more margin, not less: the bookmaker knows the buyer is looking for comfort.
Compare the double chance price against the equivalent combination you could build from 1X2 prices. If backing home and draw separately at the right stakes pays more than the 1X price, the packaged version is charging you for convenience.
Check any of this against our record
Every signal CONSENSUS publishes carries the bookmaker odds fixed before the event starts and the settled result afterwards — including the drawdowns and the losing runs. The running total is on the front page and every entry is in the log.