Q: I assume “betcha” is a slangy spelling of the way “bet you” is spoken. But I can’t figure out how “bet you” came to express certainty. Betcha know the answer.
A: The use of the verb “bet” to express certainty showed up in the US and the UK around the same time in the mid-19th century, according to written examples in the Oxford English Dictionary.
The first British citation is from the novel Tom Brown’s School Days (1857), by Thomas Hughes: “What a bore that he’s got a study in this passage! Don’t you hear them now at supper in his den? Brandy punch going, I’ll bet.” (We’ve expanded the example.)
And here’s the earliest American citation: “I saw all the ‘boys,’ and distributed to them the papers and ‘you bet,’ they were in great demand” (from the Nov. 22, 1857, issue of the Phoenix, a short-lived newspaper in Sacramento).
An expanded version of the expression, “you bet you,” appeared in Mark Twain’s Roughing It (1872), an account of his travels in the Wild West: “Hank Monk said, ‘Keep your seat, Horace, I’ll get you there on time’—and you bet you he did, too.” We’ve expanded the OED citation.
Around the same time, various hyperbolic versions of the usage showed up (originally in the US), such as “bet your life” (1852), “bet your old boots” (1856), “bet his bottom dollar” (1866), and so on.
The OED describes these dressed-up variants as “slang asseverative phrases meaning: to stake everything or all one’s resources (upon the truth of an assertion).”
The dictionary’s first example is from the Jan. 18, 1852, issue of the Sunday Dispatch in San Francisco: “He’s around when there’s money in the pipe—bet your life on t-h-a-t.”
The “corrupt forms (I, you, etc.) betcha, betcher” showed up in the early 20th century, “representing colloq. pronunciation of bet you or your (life),” the OED says.
The dictionary’s first example is from Just William, a 1922 collection of children’s stories by the English writer Richmal Crompton: “You betcher life!”
The next OED citation is from Laughing Gas, a 1936 novel by P. G. Wodehouse about Hollywood: “ ‘You’re home-sick, what?’ ‘You betcher.’ ”
And we found this Jan. 1, 1922, Wodehouse example in Mostly Sally, a novel serialized in Maclean’s Magazine.
“I hope you are going to win, Mr. Butler,” she said.
The smile which she forced as she spoke the words removed the coming champion’s doubts, though they had never been serious.
“You betcher,” he assented briefly.
In uses like those, the “-cha” and “-cher” endings represent casual pronunciations of “you” and “your.” As the OED explains elsewhere, such uses can also be seen in “nonstandard” spellings like “ain’tcha” and “aren’tcha,” which date from the early 20th century.
This citation from the OED mentions all three usages: “Comic strips and some other contemporary literature (literachoor) recognize the prevalence of these forms in speech by spelling them that way: aintcha, arentcha, betcha, etc.” (Scientific American, August 1955).
As for the early etymology of “bet,” the OED says the word is “of uncertain origin” and it’s unclear “whether the noun or the verb was the starting-point.”
The dictionary defines the noun as “the backing of an affirmation or forecast by offering to forfeit, in case of an adverse issue, a sum of money or article of value, to one who by accepting, maintains the opposite, and backs his or her opinion by a corresponding stipulation.”
The earliest Oxford example is from a 1591 collection of stories by the Elizabethan writer Robert Greene about the tricks of coney catchers, or swindlers: “Certaine olde sokers [drunkards], which are lookers on, and listen for bets, either euen or odde.” (The archaic slang term “coney catcher” comes from “coneys,” or tame rabbits, raised for eating.)
When the verb “bet” first appeared, the OED says, it meant what it usually means now: “To stake or wager (a sum of money, etc.) in support of an affirmation or on the issue of a forecast.”
The dictionary’s earliest example, dated with a question mark at some time before 1600, is from an anonymous Robin Hood legend: “Said the bishop then, Ile not bet one peny.”
The next Oxford citation is from Shakespeare’s Henry IV, Part 2, believed written in the late 1590s: “Iohn a Gaunt loued him well, and betted much money on his head.”
John Ayto writes in his Dictionary of Word Origins that the appearance of the noun “bet” in Greene’s book about the tricks of swindlers “suggests an origin in the argot of small-time Elizabethan criminals.”
If the noun “bet” did indeed come first, Ayto notes, “the usual explanation is that it is short for the noun abet, in the sense ‘instigation,’ ‘encouragement,’ ‘support’—that is, one is giving one’s ‘support’ to that which one thinks, or hopes, may happen in the future.” (The obsolete noun “abet” meant the act of abetting a crime.)