Possible Clues:

• Coin flip, an even chance
• As like as not, to the vessel, it's not on the bottom
• A gamble - flip a coin
• Gamble a matador hopes to avoid
• Use of coin to decide
• Throw in air, coin or salad
• An even chance, like flip of coin
• Even chance like flip of the coin
• Game-show question
• It's an even chance drunk turns up with drink