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

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161–170 of 193 posts

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

#161

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 generators but rather, entropy sinks+processors.

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

#162
post #43
post #28

Earlier quoted context omitted.

Next you'll cite Bible verse.

“We toss the coin, but it is the Lord who controls its decision.” - Proverbs 16:33 (TLB)

Aye, always at the ready with His noodly appendage.

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

#163

Earlier quoted context omitted.

Hi, thanks for replying. I have no complaints about your analysis, and agree that your results strongly support the D-H-M model (that there is a slight bias in coin-flipping over all and that it is caused by precession). However, it looks like about a third of your volunteers had little or no bias, presumably due to flipping end-over-end with no precession, and about a third had a lot of precession and a lot of bias.…

Yes, there is indeed a lot of heterogeneity in the bias between flippers and we are going to put more emphasis on it in an upcoming revision. However, it's hard to tell whether there are two groups or a continuous scale of increasing bias. From our examination of the data, and continuum seem to be the more likely case, but we would need many many more people flipping a lot of coins to test this properly. Yes, trainin…

Understandable, but I guess it's hard to put much weight on this data given how easy it is to introduce the effect being studied intentionally. Were the subjects aware of D-H-M beforehand? I wasn't before today, but I've been able to fake a coin flip with precession for many years (a very useful skill for parents of two small children) and if I was participating in a study like this I would be pretty hyper-aware of how much "sideways" I was giving it.

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

#164

I am curious how this changes if we condition on it flipping in the air at least once. Can we think of this result as a mixture distribution of a fair 50/50 chance of it flips at least once, and a delta function that is 100% at the side it started on, if not flipped at all?

The paper requires that the coins flipped at least once to be counted.

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

#165
post #132

Earlier quoted context omitted.

> only 48 testers/flippers I assumed they did these coin flips were done using a machine. But I guess they wanted to test if human flippers because they wanted to make claims about the human coin flip phenomenon.

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.

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

#166

Earlier quoted context omitted.

The first thing I looked for was how high was the flip and did it land on a hard or soft surface. Neither seemed to be mentioned in the paper. From the one video I looked at, the flip seems to be a few feet high at most, and land back in the hand.

> In each sequence, people randomly (or according to an algorithm) selected a starting position (heads-up or tails-up) of the first coin flip, flipped the coin, caught it in their hand, recorded the landing position of the coin (heads-up or tails-up), and proceeded with flipping the coin starting from the same side it landed in the previous trial (we decided for this “autocorrelated” procedure as it simplified record…

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

#167

Earlier quoted context omitted.

> In each sequence, people randomly (or according to an algorithm) selected a starting position (heads-up or tails-up) of the first coin flip, flipped the coin, caught it in their hand, recorded the landing position of the coin (heads-up or tails-up), and proceeded with flipping the coin starting from the same side it landed in the previous trial (we decided for this “autocorrelated” procedure as it simplified record…

[flagged]

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

#168

Earlier quoted context omitted.

Hi, thanks for replying. I have no complaints about your analysis, and agree that your results strongly support the D-H-M model (that there is a slight bias in coin-flipping over all and that it is caused by precession). However, it looks like about a third of your volunteers had little or no bias, presumably due to flipping end-over-end with no precession, and about a third had a lot of precession and a lot of bias.…

Yes, there is indeed a lot of heterogeneity in the bias between flippers and we are going to put more emphasis on it in an upcoming revision. However, it's hard to tell whether there are two groups or a continuous scale of increasing bias. From our examination of the data, and continuum seem to be the more likely case, but we would need many many more people flipping a lot of coins to test this properly. Yes, trainin…

[flagged]

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

#169

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…

Re: Low FPS webcam - here's an approach that attempts to analyze coin tossing data from the _sound_ rather than the _video_, since sound is typically recorded at a much higher sampling rate (high enough to "hear" the spinning of the coin). https://cs.stanford.edu/~kach/can-one-hear-the-fate-of-a-coi...

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

#170

Earlier quoted context omitted.

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…

Sandy Miller is widely considered to be the best volleyball player of all time. He would famously wear the same unwashed shorts every game for good luck. Maybe this was his trick.
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