Fair coins tend to land on the side they started (2023) • Hacker News Board

Re: Fair coins tend to land on the side they started (2023)

#191

Post by fbartos » Wed, Nov 20, 2024, 3:37 PM UTC

PittleyDunkin wrote: post #177

fbartos wrote: post #141

Hi, I'm the first author of the manuscript, so I thought I could answer some of the questions and clarify some issues (all details are in the manuscript, but who has the time to read it ;) Low RPM tosses: Most of the recordings are on crapy webcams with ~ 30FPS. The coin spin usually much faster than the sensor can record which results in often non-spinning-looking flips. Why did we take the videos in the first place…

How do you control against the prospect of your coin flippers being biased in terms of the videos people choose to upload?

We did not. However, we find it highly unlikely since everyone was incentivised to upload as much as possible, and the number of coin flips determined the order of the manuscript. Also, we did some basic analyses to check irregularities in the uploaded sequences, and we did not find any issues.

Re: Fair coins tend to land on the side they started (2023)

#192

Post by cbsmith » Wed, Nov 20, 2024, 5:35 PM UTC

lupire wrote: post #189

cbsmith wrote: post #94

Earlier quoted context omitted.

There's a "fair coin", and then there's a "fair flip". It's actually pretty difficult to do a truly "fair flip".

A fair coin is just a coin. There is no such thing as an unfair coin, unless its third side is so huge that it can't be reasonably called a coin.

You're going to have a lot of fans amongst con men. ;-)

Unfair coins very much do exist: https://izbicki.me/blog/how-to-create-an-unfair-coin-and-pro...

Re: Fair coins tend to land on the side they started (2023)

#193

Post by QuantumGood » Wed, Nov 20, 2024, 8:18 PM UTC

fbartos wrote: post #141

Hi, I'm the first author of the manuscript, so I thought I could answer some of the questions and clarify some issues (all details are in the manuscript, but who has the time to read it ;) Low RPM tosses: Most of the recordings are on crapy webcams with ~ 30FPS. The coin spin usually much faster than the sensor can record which results in often non-spinning-looking flips. Why did we take the videos in the first place…

Couldn't a bit of a Benford's Law curve be at work with the lesser flippers? Assuming a minimum full flip, results begin with:

1.0 flip, lands on side it started

1.5 flips, lands on opposite side

2.0 flips, lands on side it started

etc