## What is Book of Odds?

Book of Odds is the world’s first reference on the odds of everyday life. It is a destination where people come to learn about the things that worry or excite them, to read engaging and thoughtful articles, and to participate in a community of users that share their interests and ambitions.

For over three years we have been building what we believe is the missing dictionary, one filled not with words, but with numbers – the odds of everyday life. It contains hundreds of thousands of Odds Statements, from the odds of being the only one to survive a plane crash, to the odds of having a heart attack, to the odds of having ever eaten cold pizza for breakfast. Book of Odds not only allows you to search for those odds that concern or interest you the most, but also to understand probability by comparing the odds of unfamiliar events to others you have personally experienced. Book of Odds was built for you, and we hope you’ll enjoy it.

If you're wondering how you can use the site, check out our Getting Started page.

## Odds, Probability, and Chances

At Book of Odds we treat these terms as synonymous. Odds Statements are statements of probability. So, “The odds of…” should be interpreted mathematically as “The chances of…,” or “The probability of…,” or, the ratio of favorable outcomes to total outcomes. This is a subtle but important convention to be aware of when using the site. Its purpose is to be simple, accessible, and consistent with conversational English.

Traditionally, the term “odds” refers to the ratio of favorable to non-favorable outcomes. So, a gambler might say, “a horse that is expected to win 25% of the races it enters has 3 to 1 (3:1) odds against or 1 to 3 (1:3) odds to win.” This is a great tool for a bettor who is attempting to calculate the expected value of a gamble. However, this form is troublesome for ordinary people trying to understand complex statistics. “1 in 4” is easier to grasp in your mind’s eye than “3 to 1 against” – you can picture it, can’t you? It is also the way we humans think and speak when discussing uncertainty. To the mathematicians in our audience, please bear with us.

## What Book of Odds isn’t

Book of Odds is not in the business of predicting the future. We are far too humble for that. At its core, Book of Odds is retrospective – the vast majority of our Odds Statements are based on past counts and surveys. We believe that by looking at the past we can come to a greater understanding of the world and what is forever an uncertain future. We hope you will keep this limitation in mind when exploring the site.

Book of Odds is not a substitute for expert advice – We do not provide personal probabilities. The odds we report apply to groups of people. Book of Odds can tell you what the odds of having a disease are for a population but not for you personally. For this, please consult your physician.

Though we may contain information about dice, cards, coins, and other games of chance, Book of Odds is not a gambling site. The only advice we can provide is that in the long-run the house always wins. Trust us.

Book of Odds is not a search-engine, decision-engine, knowledge-engine, or any other kind of engine…so please don’t compare us to Google™. We did consider the term “probability engine” for about 25 seconds, before coming to our senses.

Book of Odds is not infallible. Our researchers are extremely rigorous. Even so, we cannot possibly be perfect. We work with millions of data points and, given enough opportunities, even rare events will occur. If you find an error, please let us know and we will fix it as fast as we can.

Book of Odds is never finished. Every day new questions are asked that we cannot yet answer. That’s part of what makes this project so exciting – we are forever expanding. We hope you’ll get involved and contribute to Book of Odds.