A saying without a clear birth date
“Lucky seven” is a familiar phrase in English, and it is natural to ask when and where it began. The honest answer is that no single origin has been established. The phrase seems to belong to the period when American English produced many such catchphrases, and it is common in the twentieth century, but dictionaries and historians of language do not agree on a first use that can be pinned down with confidence. What can be done is to explain why seven was ready to become a favourite, and to describe the ways the phrase has been used.
Like other lucky-number sayings, the phrase expresses a belief that people hold, or play with, not a fact about the number. Many speakers use it lightly, as a cheerful figure of speech.
Why seven was already prominent
Seven had a long history before the phrase existed, and that history gave the idea of a special seven plenty to build on.
- The week. The seven-day week is very old, and in many languages it is the most familiar cycle of seven that people live with. The week has its own history, and it is easy to see how a number met every day of one’s life might feel familiar and settled. The idea of seven days is also tied, in Jewish and Christian tradition, to the account of creation and the Sabbath.
- The heavens. Ancient astronomers counted seven moving bodies in the sky visible without instruments: the Sun, the Moon and five planets. Many ancient and medieval writers made use of this grouping, and the idea of seven heavens appears in both Jewish and Islamic writing. Wider ancient associations are covered under seven in antiquity.
- Lists of seven. English readers inherit groupings of seven from several sources: the seven wonders of the ancient world, the seven deadly sins and virtues, the seven seas, and the seven ages of man in Shakespeare’s As You Like It. A number that appears in so many well-known lists begins to feel like a natural number for completeness.
None of these lists is a lucky list on its own terms. The seven deadly sins, for instance, are a moral catalogue. But together they make seven a number of weight in the culture that English draws from.
Fortunate sevens in folk belief
Folk belief gave seven further associations that are closer to luck. A widely repeated English and European tradition holds that a seventh son, and especially the seventh son of a seventh son, has unusual gifts such as healing. The idea turns up in older folklore in various forms, and its details vary. Seventh heaven, in English use since at least the nineteenth century, became a figure of speech for great happiness, borrowing from the idea of the highest of the heavens.
Elsewhere, other traditions have their own fortunate sevens. Japan has a group of deities known as the Seven Lucky Gods, a separate tradition with its own history that should not be confused with the English phrase. Cases like this show that seven is favoured by several cultures for reasons that do not all trace to the same source.
Seven in modern idiom
In twentieth-century American English, seven acquired a particular role in games and sport. A standard six-sided die is made so that opposite faces add to seven, which means the number seven is built into the object itself, and any two dice can add to seven in more ways than to any other total. That is a fact of arithmetic, not luck, but it is probably part of why seven has been talked about in game settings. Adding the numbers: with two dice there are 36 equally possible pairs of faces, and six of them add to seven, which makes seven the most frequent total. Knowing that does not help predict any single throw.
In baseball, the seventh inning has a reputation of its own. The “seventh-inning stretch”, when spectators stand and sing, is a long-standing custom in American ballparks. Stories about how it began, including one attached to a president attending a game, are often repeated, but the true origin is uncertain, and it is best treated as a tradition whose beginning is unknown. The expression “lucky seventh” for that inning is a sporting echo of the broader phrase and not evidence of where it started.
Competing explanations
Writers who try to explain the phrase usually offer one of three accounts.
- Religious inheritance. Seven is sacred or complete in the Bible and in the traditions around it, so it is lucky by association. This is plausible as a background, though it does not explain why the English phrase uses “lucky” instead of “holy” or “perfect”.
- Games. The behaviour of dice, and the special place of seven in some games, made seven a number people associated with fortune. This is consistent with the arithmetic above but does not date the phrase.
- Sound and rhythm. “Lucky seven” is short and easy to say, with a rhythm that suits an idiom. Such phrases spread because they are pleasant, not because they encode a reason.
These can all be true together, and a historian would say that a phrase like this seldom has a single cause.
What can be said with confidence
It can be said that seven was an unusually prominent number in the religious, calendar and literary heritage of English speakers, that folk belief gave it fortunate associations, and that “lucky seven” is a common phrase in modern English. It cannot be said, on present evidence, who first used the phrase or why. Anyone who gives a confident origin story, such as a single named person or event, is going beyond what the sources show.