--- title: Why the Coin Toss is Random description: We all know that there's a roughly 50-50 chance the coin will land on either side. But, when a robot tosses the coin, it'll fall precisely on one side each time. So what if the coin toss isn't really because of the coin's weight? canonical: https://time.com/4040408/why-the-coin-toss-is-random/ author: Ainissa Ramirez article:opinion: false article:content_tier: free article:published_time: 2015-09-18T19:21:05.000Z article:modified_time: 2026-03-30T11:52:20.894Z article:section: Science og:title: Why the Coin Toss is Random og:description: Heads you win, tails you lose. og:url: https://time.com/4040408/why-the-coin-toss-is-random/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt6d46fcfc7c4e472e/698864382dce01779b9e5944/1920-coin-toss.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 og:image:width: 1200 og:image:height: 675 og:image:alt: Matthew Slater, Devin McCourty, Stephen Schilling og:type: article twitter:card: summary_large_image twitter:title: Why the Coin Toss is Random twitter:description: Heads you win, tails you lose. twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/blt6d46fcfc7c4e472e/698864382dce01779b9e5944/1920-coin-toss.jpg?branch=production&width=3840&quality=75&auto=webp&crop=16:9 ---  # Why the Coin Toss is Random by [Ainissa Ramirez](https://time.com/author/ainissa-ramirez/) and [Salima Koroma](https://time.com/author/salima-koroma/) Sep 18, 2015 7:21 PM UTC  New England Patriots captains wide receiver Matthew Slater (18), free safety Devin McCourty (32) and center Stephen Schilling (63) participate in the coin toss during Super Bowl XLIX against the Seattle Seahawks at University of Phoenix Stadium on Sunday, February 1, 2015, in Glendale, Ariz. (AP Photos/Ben Liebenberg) New England Patriots captains wide receiver Matthew Slater (18), free safety Devin McCourty (32) and center Stephen Schilling (63) participate in the coin toss during Super Bowl XLIX against the Seattle Seahawks at University of Phoenix Stadium on Sunday, February 1, 2015, in Glendale, Ariz. (AP Photos/Ben Liebenberg)Ben Liebenberg—AP by [Ainissa Ramirez](https://time.com/author/ainissa-ramirez/) and [Salima Koroma](https://time.com/author/salima-koroma/) Sep 18, 2015 7:21 PM UTC The coin flip is so synonymous with randomness that the phrase has become a metaphor for unpredictability itself. We even trust the coin toss with our nation’s most popular sport: Every NFL game begins with a flip to decide which team will kick or receive. But while everyone intuitively knows there’s a roughly 50-50 chance the coin will land on either side, few understand exactly what makes a coin toss random in the first place. Watch the video to find out the answer. ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/4040408/why-the-coin-toss-is-random/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/4040408/why-the-coin-toss-is-random/"},"headline":"Why the Coin Toss is Random","datePublished":"2015-09-18T19:21:05.000Z","dateModified":"2026-03-30T11:52:20.894Z","description":"Heads you win, tails you lose.","url":"https://time.com/4040408/why-the-coin-toss-is-random/","keywords":[],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blt6d46fcfc7c4e472e/698864382dce01779b9e5944/1920-coin-toss.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Ainissa Ramirez","jobTitle":null,"url":"https://time.com/author/ainissa-ramirez/"},{"@type":"Person","name":"Salima Koroma","jobTitle":null,"url":"https://time.com/author/salima-koroma/"}],"articleSection":"Science","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blt6d46fcfc7c4e472e/698864382dce01779b9e5944/1920-coin-toss.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"Matthew Slater, Devin McCourty, Stephen Schilling","caption":"Matthew Slater, Devin McCourty, Stephen Schilling","creditText":"Ben Liebenberg—AP","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/science/","name":"Science"}},{"@type":"ListItem","position":2,"item":{"@id":"https://time.com/4040408/why-the-coin-toss-is-random/","name":"Why the Coin Toss is Random"}}]}] ```