odds

The word grows from odd in its sense of "uneven." That unevenness still shows in Christopher Marlowe's Tamburlaine the Great (c. 1587–1588), where a thousand horsemen against five hundred foot is "an ods too great." Today the word is plural-only and takes a plural verb: the odds are in favor. Keep it apart from probability itself: odds of three to one mean a three-in-four chance.

A bookmaker's odds are a price, not a measurement. They say how much a winning stake returns, and bookmakers give or offer them. They are easily mixed up with the probability ratio, but they are read differently. When the odds on a horse shorten, the return on each unit staked shrinks, whatever the horse's real chances.

A chess handicap named for what is conceded: knight odds, rook odds, time odds. The stronger player gives them. In 1913, The British Chess Magazine wrote of "Knight-odds parties," hyphenated as a modifier. Raymond Keene's The Simon & Schuster Pocket Book of Chess (1989) calls material odds rare and credits the chess clock with making time odds possible: a minute or two for all one's moves.

An ordinary countable plural with a singular beside it: one odd, two odds, as when a list sorts the evens from the odds. It belongs to the noun odd, meaning an odd number or a leftover item. Don't confuse it with the plural-only odds of chance, which has no matching singular in everyday use.