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

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

#181

Post by oefnak »

saagarjha wrote: post #165
halgir wrote: post #132

Earlier quoted context omitted.

If you programmed a machine to flip a coin in the same exact way every time, would you not expect the coin to land the same way every single time? If you program some randomness into the machine to simulate human flipping, then you'd simply move scrutiny from the coin to the machine's programming. I think the result could be better described as "humans tend to flip fair coins to land on the side they started".

One would expect chaos effects to come into play.

One might, but that would be wrong.

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

#182

Post by bigbacaloa »

bgroat wrote: post #27

This has been commonly known by magicians for decades. I doubt that any single magician had conducted 350k flips, but I know I personally did ~2,500 to test the effect when I was a kid. And I'm sure if you got 30 magicians together to pool data we'd have a meta-analysis of about this size but with experiments a century ago

[dead]

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

#183

Post by moi2388 »

Green-Man wrote: post #150
pc86 wrote: post #143

Earlier quoted context omitted.

Perhaps whether it's a Department or a Ministry could be decided randomly.

Randomly how? By a coin toss? Who will toss then? How many times? How skilled the participants should be? All these important questions must be decided by some authority. Sort of a Department of Equal Distribution. Or a Ministry of Fair Tosses. Wait a second...

The obvious solution is to hand it off to the Department of Catch 22. Or the Ministry of infinite recursion. Wait..

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

#184

Post by M95D »

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…

I have a question about the ethics of this study.

Were you not concerned that a study that shows a bias in coin flipping would undermine the trust people have in this simple method settling arguments, leading to even more arguments between people, possibly fights and injuries, in situations where a coin flip would have settled an existing argument?

Thank you.

PS: This isn't supposed to to be a serious question, if anyone has doubts. :)

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

#186

Post by lupire »

bambax wrote: post #120
acyou wrote: post #96

The paper looks like it has a large sample size, but it actually has a sample size of only 48 testers/flippers. Some of the videos of those testers show very low, low-rpm coin tosses, we're talking only 1-2 flips. Where they also flipped thousands of times, presumably in the same way. So there is actually a very small sample size in the study (N = 48), where testers that don't flip properly (low rpm, low height, few…

The real lesson is probably that if you're skilled enough, and/or train for long enough, you can influence the odds significantly without anyone ever noticing anything.

That has been known for decades. It's not the lesson of this paper.

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

#187

Post by skykooler »

dfxm12 wrote: post #131
chongli wrote: post #122

Earlier quoted context omitted.

Yes and what immediately jumps out to me as a source of bias is that they asked this small group of 48 coin flippers to flip thousands of times each. I would’ve thought it would be obvious that when you ask people to do something thousands of times they might do it in a different (and biased) way than someone doing that thing only once. Get a hundred thousand people to flip a coin once each and then see what happens!

Get a hundred thousand people to flip a coin once each and then see what happens! Of all the stats we collect in sports, I wonder if someone has info on coin tosses in sports like American Football, Tennis, etc. I wonder if there are even rules regulating how a coin should be tossed in different sports...

Having stats on the outcome of coin tosses in sports wouldn't help, because it's unlikely that the state of the coin before flipping was recorded.

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

#188

Post by lupire »

FartyMcFarter wrote: post #66
steeeeeve wrote: post #65

I learned a trick with flipping coins from a barber at my grandpas shop when I was probably 6 or 7. Since then I've always been able to flip a coin and determine what the outcome is. It's really just being consistent with the flip and the catch.

If this is done with a quick toss and the coin is flipping rapidly in the air, that's pretty impressive.

It's easy. All you need to do is rotate (yaw) your hand when flipping so that the coin spins but never actually flips, or a little slower so it flips only once. A watchful eye can detect it happening, though.

You can preview the effect by spinning a coin slowly on a table.

This is a common problem in intro Physics Mechanics class.

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

#189

Post by lupire »

cbsmith wrote: post #94
noman-land wrote: post #89

Haven't read the paper yet but this is so weird because when I was a kid I noticed this phenomenon myself. I noticed I could reliably flip a coin such that when it landed it would land on the same side as it was flipped from. I was getting like 80% accuracy and I didn't even know what I was doing to achieve it. I could just usually feel when I flipped it that I "did it right". I used it a couple times to win coin tos…

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.

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

#190

Post by lupire »

mrbungie wrote: post #161
Animats wrote: post #151

Useful. This demonstrates that coin flipping merely amplifies noise in human manipulation. A classic example in the old PSSC high school physics curriculum was a little catapult-like device which tossed a coin, spinning it a few times in mid-air, and repeatably landing it on the same side. It's a demonstration that Newtonian physics is repeatable.

Yes, that's because a coin toss is not intrinsically random, but just pseudo-random due to its chaotic behaviour which is especially notable at relatively "extreme" starting conditions. But if the tosser were to control, manipulate or just don't care enough about adding entropy to the toss, those random generation qualities of the object would start to fall apart. PS: As I read before, dice/coins are not entropy gene…

What in the Universe is an entropy generator?
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