# Why do we use the plural "chances" and "odds" to talk about probability?

Probability in mathematics is just a number between zero and one. For example, we say, "The probability of this happening is fifty percent."

However, in many statements, we use "chances" and "odds", which are plural as opposed to the singular "probability". For example, consider "What are the chances of that!" and "The odds of winning the lottery are minuscule."

Dictionary definitions just tell it how it is, but not why:

You refer to how likely something is to happen as the odds that it will happen.

The following structure reads especially clunky partly because it has are next to one.

The overall odds of winning a lottery prize are 1 in 13.
CED (emphasis mine)

Again, that last part is just one number (~0.08), so we would say, "The overall probability of winning the lottery is point zero eight." Yet, we use the plural "chances" and "odds" though they refer to one number. "What is the chance of that!" and "The odd of winning the lottery is minuscule" come more intuitively to me.

• Does this answer your question? "Chances of (doing) something" vs. "chances at (doing) something"? Jan 16 at 19:02
• Aside: for odds, we don't usually use a number beween 0 and 1, but something like "a million to one!" The odds are what a bookmaker quotes for the payout from a race. It is a plural word – its singular odd has a different meaning. Jan 16 at 19:04
• @FumbleFingersReinstateMonica I don't think that's quite the same question though. They are related, for sure, but this question is about the set phrase "chances/odds are". Jan 16 at 19:04
• There's rarely if ever any difference between What is the chance of that? and What are the chances of that? Jan 16 at 19:06
• A mathematician might say "The overall probability of winning the lottery is point zero eight," but people don't often talk like that. Jan 16 at 19:11