Maybe Coin Tosses Aren’t Entirely Random After All
The results of a coin toss are random–or so we thought. But a provocative new video from YouTube’s Numberphile series turns that conventional wisdom on its head.
The video maintains that the ratio of getting heads vs. getting tails isn’t 50/50. It’s more like 51/49–with the coin more likely to come up the same way it started. So you’re more likely to get heads if the toss starts out with heads face-up, and tails if the toss starts with tails facing up.
Dr. Persi Diaconis, a professor of statistics and mathematics at Stanford University, arrived at those odds in a 2007 study in which a high-speed video camera was used to analyze a series of coin flips.
“I don’t care how hard you flip the coin, you can flip it to the moon,” Diaconis says in the video. “That bias is a provable, stable bias.”
It’s a tiny difference, of course, but it’s good to know if want to up your chances of winning a bet!