at sixes and sevens

From earlier set all (and other forms) on six and seven, from Middle English setten al at (or setten the world on) sixe and sevene (“to risk everything, take a chance”), probably a variant—either an exaggeration or mishearing—of setten on cynk (“number or throw of five on a die”) and sys (“number or throw of six on a die”), referring to the two highest throws and thus the riskiest bets on the dice in dice games. Folk etymology often links the phrase to the order of precedence of the livery companies in the City of London Corporation, in which the Worshipful Company of Skinners and the Worshipful Company of Merchant Taylors trade sixth and seventh place each year, but the phrase was already in use for a century before this practice began in 1484.

Mức độ chứng cứ: Cách giải thích dân gian