Please visit our About Book of Odds page to learn all about what Book of Odds is and isn’t.

Book of Odds employs talented researchers from top universities to create the odds of everyday life. We have a controlled process of data collection, curation, and computation that has been developed and refined over three years of practice. Computation is generally straightforward and retrospective, using empirical data to estimate probabilities. We place a high value on transparency and display a full citation for every underlying source of data used in the computation of every Odds Statement. With a bit of work any user can reproduce the vast majority of our Odds Statements.

We must remember that an Odds Statement is solely the work of Book of Odds. It is both an interpretation and a computation of data provided by its underlying sources. These sources do not produce, endorse, or claim validity for any Odds Statement. The data they provide are simply input into our research process. Book of Odds works to obtain permission when using private or copyrighted data. If you have any questions or concerns about data usage, please contact our permissions team.

Computation is just half the battle. Once data have been collected, analyzed, and the odds have been computed, every Odds Statement then undergoes a rigorous quality review, is modeled ontologically, and finds its place in our underlying semantic database of probabilities.

Book of Odds addresses an important and widespread need: the need to understand risk simply and accurately. In many ways our lives are shaped by the avoidance or management of uncertainty. Until Book of Odds, there existed no large-scale reference for learning about and understanding this profoundly critical concept.

An Odds Statement is the basic unit of Book of Odds. It is a concise statement of probability of the form: The odds a person will be struck by lightning in a year are 1 in 835,500 (US, 1995-2007). Think of an Odds Statement as analogous to an entry in a dictionary. It follows a consistent set of conventions making it easy to understand and compare to any other. Book of Odds contains hundreds of thousands of carefully researched Odds Statements. Learn more in the How To Use Book of Odds section.

The idea of calibration is central to the mission of Book of Odds. Simply put, calibration is learning by comparison. It is the act of understanding the unfamiliar by relating it to the familiar. Despite common wisdom, we believe that people can learn to understand probability intuitively if given a consistent reference full of vivid examples to work with. Using calibration you will be able to make unexpected connections and increase your understanding of uncertainty. Learn more in the How To Use Book of Odds section.

The underlying source information is available for every Odds Statement. Check out the “Sources and Definitions” section on any Odds Statement page to find citation and glossary information. The Source citations will be at the top of this section.

Book of Odds covers a wide variety of topics from health-related information like cancer and diabetes to sex and relationships. Our website is currently organized into four topical portals ( Health & Illness, Relationships & Society, Daily Life & Activities, and Accidents & Death) all of which are made up of many subtopics.

Book of Odds has many different search tools for exploring the odds of everyday life. Please visit our Getting Started page to learn how to find anything that you are looking for.

Search results are ranked using a Book of Odds algorithm that takes into effect many different factors such as relevance, calibration value, quality, readability, user interest, and others.

Don’t worry, we get this question a lot. Book of Odds is large, but don’t be intimidated. Every piece of content on Book of Odds is indexed into a topical area. This provides users an easy way to browse contextually related content. Try out a search, read a featured article, or explore a tag or topic. Our content is related on many dimensions; dive in and see where you end up!

Odds Statements make great fodder for research papers or school projects. Using the search function is a great way to find specific information related to your research. To keep track of your research you can register with Book of Odds and use our Custom List functionality. This tool will let you save and organize any Book of Odds content on the fly.

It is also a good idea to explore the topical area that best matches your field. We are constantly publishing new articles that may interest you or give you ideas. Finally, every Odds Statement contains a full citation for each underlying data source. We encourage all users to check these out. (If we don’t provide a URL, try putting the citation in a search engine and you'll likely find it right away!). If a particular Odds Statement or topic interests you, these sources are a great place to learn more.

Our researchers go to extreme efforts to use only the best, most complete, and readily available data in the world. We have an extremely rigorous quality control process so you can be sure that every number is double and triple checked. Even so, when dealing with millions of data even a very low rate of error will result in many mistakes. Please help us identify problems by reporting errors. We will investigate every error report and make any required corrections as quickly as we can.

Further, every Odds Statement is evaluated and graded for its reliability. We also assign a “Confidence” rating to each Odds Statement that reflects the quality, representativeness, and applicability of the underlying data upon which the Odds Statement is based. This evaluation is graphically represented on each Odds Statement page. A low rating does not mean an Odds Statement has no value, just that it did not fully meet our strict standards for quality. Many of our most interesting Odds Statements have a less-than-perfect rating. It is important to note that there is huge variability in data quality and collection standards across industries and topical areas. For example, the data supporting Health & Illness is generally very good (large, well maintained data sets or controlled clinical studies) whereas data collected by a small industry association might be less rigorous due to the disjointed nature of the business it represents. Yet, we hold both to the same standard of quality. In either event, you can be confident that Book of Odds has done its due diligence in seeking out the best data available for computing odds.

Finally, we have a special designation called “Speculative Entry.” Odds Statements marked as speculative are generally based on several assumptions or case studies and often employ some more creative estimation methods. These Odds Statements are typically of a fun and whimsical nature, and often deal with subjects that are not easily quantified. Odds Statements holding this designation should be considered less reliable. However, they can be of great value due to their uniqueness and inherent interest.

A thread is a sequence of Odds Statements that tells a story. It may begin with a large population, say the number of people in the US and then follows a sequence of independent and contingent probabilities to get to more and more specific subsets of the larger group. Some operate in time, following the survival rate of a given deadly disease or show a diagnostic pathway. Others we call “destiny threads” since they follow a group (say 7 to 11 year old baseball players) through the odds of making it to the Baseball Hall of Fame. Others reveal the odds of behaviors in action. For example, the odds of contraceptive failure in use are much higher than the odds of failure in a laboratory setting. Threads of this sort tell the story of surprising outcomes. Threads can be very revealing or great fun. They often focus on goals people hope to accomplish or risks they wish to avoid.

The parentheses at the end of every Odds Statement contain two important pieces of information. The first represents the geography to which the Odds Statement applies. The second is referred to as the Data Span and represents the period of time over which the data used to calculate the Odds Statement was collected. Please read our Methodology section to learn more.

Book of Odds is a free reference for all to enjoy and use. All we ask is that you cite us. If you are referencing us on the Web, please link back to Book of Odds. Within the “Sources and Definitions” section of each Odds Statement page you will find a suggested citation for Book of Odds that you can copy and paste onto any document utilizing an Odds Statement.

For articles, please use the citation: "Author, Title of article, http://www.bookofodds.com (Accessed: MM/DD/YYYY)".

The confidence rating is a representation of the confidence Book of Odds has in the underlying data sources used to calculate the Odds Statement. To learn more about confidence rating please see the question “How reliable are your Odds Statements?” and read our Methodology section.

A tag is a device for building relationships between content that are not inherent in the topical hierarchy of the site. Tags allow us to take cross-references of all the topical areas. They are a great way to reorganize data and find interesting comparisons across topical areas.

If you find an Odds Statement to be of particular interest you can use the “Interesting” button appearing alongside every Odds Statement to essentially give it your virtual “thumbs up.” Over time, the use of this function will allow for the most interesting content we have to bubble up to the top. Clicking it will also save the Odds Statement to your list of “Interesting Odds” on you’re My Book of Odds page. As this list grows it becomes a great tool for calibration.

Commenting is easy and straightforward. There is a comment box at the bottom of every Odds Statement and article page. We hope you’ll get involved and join the discussion. Please comment with an open mind and treat your fellow users with respect.You must be a registered user to comment. Registration is quick and easy and will allow you to use the full functionality of Book of Odds. Click here to register.

Currently our database has several hundred thousand Odds Statements, but it is important to remember that Book of Odds is always growing. Before long we will hit one million and have a big party. Every new Odds Statement adds comparative value to all the others and, after all, Book of Odds is all about comparison. (Just 100,000 Odds Statements allow for 5 billion unique comparisons!) In several years we will have more than we know what to do with. You can help us reach this goal by Suggesting Odds.

Despite the amount of research done to create each Odds Statement, we know we aren’t perfect. We encourage users to use our Report an Error form to tell us about anything we might have missed or gotten wrong. We appreciate your help!

If you have any technical issues with the site, please let us know! Visit the Contact Us page for more information.

Please go to the Suggest Odds page to suggest any Odds Statements you want to see added to Book of Odds. If your suggestion makes it to the Book of Odds database you will be given credit as a contributor under the “Sources and Definitions” section on the Odds Statement page.

We’ll send you an email notifying we’ve received your suggestion. At that point the suggestion will be checked against our database and, if unique, it will be assigned to a researcher and put through the same process every Odds Statement has gone through. If your baby makes it to publication you’ll get an email notification and you will be given credit on the Odds Statement page.

Although we will do our best to count all the space aliens that have visited Earth, please keep in mind that some things are just unquantifiable (like Amram’s inventory of stories) and not every suggestion will be accepted.

Please use the “Report Abuse” function that is beside every comment. We will remove inappropriate or offensive comments.

We encourage webmasters and bloggers to link to Book of Odds. When linking, we'd appreciate it if you'd link to the specific piece of content you are referencing and use descriptive anchor text that includes the phrase "Book of Odds."

Generally, we encourage free use of our Odds Statements so long as proper attribution is given. If you have questions about reproducing any article or blog content, or using Odds Statements for commercial purposes, please refer to our Terms and Conditions. If you do not find what you are looking for and still have questions please contact our permissions team.

Generally, yes. However, we should note that Book of Odds tackles serious issues including sexuality, war, crime, and death. Book of Odds sternly admonishes all forms of prejudice, bigotry, and discriminatory language or actions. If you find something on the site offensive, please alert us immediately and we will look into having it removed.

We do not allow children under 13 to become registered users.

Please refer to our Terms and Conditions for further information.

Please visit the Advertise with Us section to learn more.

Book of Odds is constantly being updated. We publish new articles every day and new data is added periodically, so check back often! You can subscribe to one of our RSS feeds or our newsletter to be alerted of updates.

We use the best data available to calculate our Odds Statements. Often times the most recent data available is several years old. This is typically due to the lag time between the actual data collection, the analysis, and the eventual publishing of that data. And then of course there is our own research and quality process that takes time (which we are constantly working to reduce!). You can be sure that we will do our absolute best to keep up with new data as it is made available to us.

We have a saying at Book of Odds, “Old data is not necessarily bad data.” It is as easy to fudge the numbers today as it was 10 years ago and our researchers are constantly finding new data sources that we cannot use because we find errors or question the validity of the results. (We also reflect these judgments in our Confidence Rating of every Odds Statement.) Also, like all things, research is trendy. Some topics are neglected for years and government projects often lose funding for the benefit of other expenditures. Therefore, the very best data on a topic might be older than you!

Finally, we're a bunch of data junkies and find even historical data immensely interesting. What were the odds of surviving the Titanic? Well, these data are 100 years old! What about the Battle of Gettysburg? Even more so! We plan to back-fill Book of Odds with as much historical data as we can find because not only is history interesting, but it allows us to make fun comparisons and spot historical trends.

This is another area where you can help us by suggesting new sources of data that we may have either overlooked or not yet found.

You can use the sign-up form on the front page, or, if you are already a registered user, simply log into Book of Odds and go to the Accounts and Settings tab in the My Book of Odds section. You can also sign up during registration.

Simply log into Book of Odds and go to the Account and Settings tab in the My Book of Odds section.

Absolutely! We plan to expand geographically at a speed our success permits. Our ultimate vision is to evolve into the global Book of Odds.

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The best thing you can do to support Book of Odds is to get involved and join our community. If you like what we have to offer, tell a friend! If you can’t get enough and think you can help in more concrete ways, check out our Jobs page for openings.