True odds
The payout that would make a bet fair: losing outcomes divided by winning ones. A straight up on 37 pockets has true odds of 36 to 1.
In context
The house edgemathHouse edgeThe share of each stake the casino keeps on average: 2.70% in European roulette.Read full → is the gap between the true odds and the payoutmoneyPayoutWhat a winning bet returns, quoted as “X to 1” on top of the returned stake.Read full →. A straight upbetStraight upA single number, pays 35:1.Read full → pays 35 to 1 against true odds of 36 to 1; the missing unitmoneyUnitThe base stake a system or a player works in. Progressions are described in units so they apply at any table.Read full →, shared over 37 spins, is the 2.70%.
The craps “odds” bet pays true odds and has no house edge at all, which is why a casino lets you make it only on top of another bet.