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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)

#91

Post by burningChrome »

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.

This is anecdotal evidence but Dennis Rodman (the pro basketball player) was the greatest rebounder of all time. One of his teammates related to how he would watch guys shoot (usually during warmups) and count the rotation of the ball. Based on how many times the ball would rotate, he knew if it was going in or not and then would position himself to get the rebound.

I would imagine OP did something similar. Watch the coin as its rotating and then grabbing it and then flipping to the side he predicted.

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

#93

Post by whythre »

BiteCode_dev wrote: post #87
hackernewds wrote: post #84

Earlier quoted context omitted.

a coin is likely to land on the same side. it was flipped from if it was tossed by a machine at low RPM and height consistently* there's your paper

I'm sure you will find similar behavior with dice if you just gently let them fall from your hands instead of throwing them across the table. This is silly.

Somebody’s grant money getting thrown down a hole…

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

#94

Post by cbsmith »

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".

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

#95

Post by Frummy »

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…

Maybe you were like one with the coin and always pushed it the optimal way for like the same type of movement and direction and rotation for the same amount of rotations in air etc like perfected an initial condition and kept it stable like it rotated 6 times and landed the same way

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

#96

Post by acyou »

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 coin rotations) can affect the results disproportionately.

Doesn't look like the study author backgrounds are particularly focused on statistics. I would presume with 48 authors (all but 3 of which flipped coins for the study), the role of some might have been more test subject than author. And isn't being the subject in your own study going to introduce some bias? Surely if you're trying to prove to yourself that the coins land on one side or another given some factor, you will learn the technique to do it, especially if you are doing a low-rpm, low flip. Based on the study results, some of the flippers appear to have learned this quite well.

If the flippers (authors) had been convinced of the opposite (fair coins tend to land on the opposite side from which they started) and done the same study, I bet they could have collected data and written a paper with the results proving that outcome.

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

#97

Post by ummonk »

BiteCode_dev wrote: post #90
thrw42A8N wrote: post #76

Earlier quoted context omitted.

Is it unlikely? If I didn't read your comment I wouldn't see any problem there. I never saw anyone flipping a coin in a different way. It's just not done much around me.

If you claim to do a research on coin tossing, the minimum is to be aware on how people toss coin. The whole purpose of tossing a coin is randomness, so of course you want high and fast. If the result was that no matter how high and fast you throw is you get this bias, it would have been interesting. But now you just say "if you do things badly, things don't work".

No, the whole point of the paper (and the physics model it is verifying) is to see what happens in normal human coin tosses.

If you want to measure what happens specifically with high and fast coin tosses, then that’s an entirely different study to be done.

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

#98

Post by dotancohen »

roccomathijn wrote: post #88
hammock wrote: post #80

Earlier quoted context omitted.

The guy in the grandparent YouTube video suggests shaking the coin in a closed hand (or better, a box) to randomize the starting side and then transferring it unseen to someone else to flip it Craps is also brought to mind where the dice have to bump the back wall

Let's abandon coin flipping in favour of coin shaking then

It's a shake and then a flip. Put your hand on your hip and bend your knees in tight.

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

#99

Post by philipov »

ummonk wrote: post #97
BiteCode_dev wrote: post #90

Earlier quoted context omitted.

If you claim to do a research on coin tossing, the minimum is to be aware on how people toss coin. The whole purpose of tossing a coin is randomness, so of course you want high and fast. If the result was that no matter how high and fast you throw is you get this bias, it would have been interesting. But now you just say "if you do things badly, things don't work".

No, the whole point of the paper (and the physics model it is verifying) is to see what happens in normal human coin tosses. If you want to measure what happens specifically with high and fast coin tosses, then that’s an entirely different study to be done.

I don't know what a normal human coin toss is. Does the paper contain evidence/argument to justify their way of flipping a coin as "normal"?

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

#100

Post by Tetraslam »

Frummy wrote: post #95
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…

Maybe you were like one with the coin and always pushed it the optimal way for like the same type of movement and direction and rotation for the same amount of rotations in air etc like perfected an initial condition and kept it stable like it rotated 6 times and landed the same way

the Force is with them
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