FiveThirtyEight

538, originally rendered as FiveThirtyEight, was an American website that focused on opinion poll analysis, politics, economics, and sports blogging in the United States. Founder Nate Silver left in April 2023. On September 18, 2023, the original website domain at fivethirtyeight.com was closed and web traffic became redirected to ABC News pages. The logo was replaced, with the name 538 now used instead of FiveThirtyEight.

The website, which takes its name from the number of electors in the United States electoral college, was founded on March 7, 2008, as a polling aggregation website with a blog created by analyst Nate Silver. In August 2010, the blog became a licensed feature of The New York Times online and was renamed FiveThirtyEight: Nate Silver's Political Calculus. In July 2013, ESPN acquired FiveThirtyEight, hiring Silver as editor-in-chief and a contributor for ESPN.com; the new publication launched on March 17, 2014. Since then, the FiveThirtyEight blog has covered a broad spectrum of subjects including politics, sports, science, economics, and popular culture. In 2018, the operations were transferred from ESPN to sister property ABC News (also under parent The Walt Disney Company).

During the presidential primaries and general election of 2008 the site compiled polling data through a unique methodology derived from Silver's experience in sabermetrics to "balance out the polls with comparative demographic data". Silver weighted "each poll based on the pollster's historical track record, sample size, and recentness of the poll".

Since the 2008 election, the site has published articles—typically creating or analyzing statistical information—on a wide variety of topics in current politics and political news. These included a monthly update on the prospects for turnover in the Senate; federal economic policies; Congressional support for legislation; public support for health care reform, global warming legislation and LGBT rights; elections around the world; marijuana legalization; and numerous other topics. The site and its founder are best known for election forecasts, including the 2012 presidential election in which FiveThirtyEight correctly predicted the vote winner of all 50 states and the District of Columbia.

FiveThirtyEight has won numerous awards. These include Bloggie Awards for Best Political Coverage in 2008 and Best Weblog about Politics in 2009 as well as Webbies for Best Political Blog in 2012 and 2013. While under the ownership of ESPN in 2016, FiveThirtyEight won the Data Journalism Website of the Year award from the Global Editors Network.