The paper shows some significant evidence that human coin flips are not as fair as I would have expected (plus probably a bunch of people would agree with me). There’s always some probability that this happened by chance, but this is pretty low.
Of course, we should be able to build a really accurate coin flipping machine, but I never would have expected such a bias for human flippers.
This is why science is awesome and challenging your ideas is important.
Edit: hopefully this is not too wrong a place, but Lemmy is small, and I didn’t know where else I could share such an exciting finding.
My favorite part is this:
Funding The authors have no funding to declare, and conducted this research in their spare time.
“Funding: my mom gave me the coins out of her car cupholder”
I, too, was a poor grad student.
At that time I didn’t have a child to suck the life out of me. Just a dissertation.
(My hypothesis is that the child is worse, but my wife won’t let me conduct double blind, placebo controlled studies. Fortunately, we didn’t have twins…)
It’s just bizarre how high quality this evidence is. It’s probably because it’s so cheap to collect this data, and other science nerds are also science geeks like me.
Actual video of this many tests. Just data orgasm.
here it’s not ready yet.
with their spare change
tl;dr:
The standard model of coin flipping was extended by Persi Diaconis [12] who proposed that when people flip a ordinary coin, they introduce a small degree of ‘precession’ or wobble—a change in the direction of the axis of rotation throughout the coin’s trajectory. According to the Diaconis model, precession causes the coin to spend more time in the air with the initial side facing up. Consequently, the coin has a higher chance of landing on the same side as it started (i.e., ‘same-side bias’).
“Higher chance” being 50.77% to land on the same side it started from. But this varies by person; apparently some people introduce more precession than others. But even if you could figure out how to do it reliably, I wouldn’t bet the farm on it.
The illusion of a coin flipping in the air allows those that have mastered the act to get near 100% precision.
Crazy how simple and obvious that seems after you see it, but I never would have suspected it if someone did it right in front of me.
Right??
Omg. I must learn this.
Shit. I have zero cash in my house.
I tried for a few minutes, before my son got bored and wanted to move on 😜. If you do learn it, let us know!
How old is your son? I imagine I’ll do the same, but this is the only magic trick that I’ve really wanted to learn. My son has some fine motor delays so he won’t be able to do this.
I realized that I’ve interacted with you a few times here, so I ended up looking at your comment history. We seem to share a lot of similar characteristics.
I noticed that you’re trans and had a Q&A. I’m cis-het and I missed that session. I hope that we’ll interact again. I want to understand T as well as I understand LGB. I just don’t know anyone T.
My boy is about 15 now. I miss the times when magic was, well, magic. I love the times we have now, and look forward to the future as well. But, I’d be lying if I said that I didn’t miss my little boy.
If you have any Q’s, ask away. I may do another AMA soon, for fun.
I’m curious why you don’t think this is significant?
This is a pretty high house edge (or whatever you want to call it) for a game that seems the most fair as possible.
No casino games are that fair.
As is discussed elsewhere in this thread, you could probably practice and get that higher.
Where are coins flipped multiple times in order to gain such value from doing so? I can only think of 2up being played in Australia, 1 day per year and they don’t flick it with their thumb, so…
Where is the “house” gaining so much?
You can bet on dice and coin flips.
“I bet you a dollar that my coin flip will come up heads?”
This research suggests that this is not only profitable, but can be improved upon.
Edit: so weird. Why would such a simple and correct statement be controversial? I would’ve thought that betting on heads or tails was not this far out of fair coin odds.
I think the question is, where can you bet on a single coin flip? Maybe because I’m Australian, there’s only one day a year you can bet on a (two) coin flip legally here. Everyone else seems to generally understand that coin flips aren’t fair for gambling and therefore is illegal.
If this paper was like ‘this is how corruption in sports…’ rather than ‘this is like that magician cup and balls trick’ then I’d understand your concern.
But like you said, you don’t even have a coin in the house, so the practical side is day to day, perhaps not even once a year, not only are you not deciding on a coin flip, even if you were, you’d (or whomever was flipping it for you) have to learn a technique to see it affect you.
Aside from National Lampoon Vegas Vacation, it would be in back alleys. It’s not a commercial game because it’s not exciting enough and it would be easy enough to fool with a machine (also the paper at hand). I just didn’t expect it to be so biased for actual people flipping coins.
I seem to have confused people. I just thought there was a different understanding and didn’t want to explain gambling.
What I meant to express in “the house always wins” is that in games of chance, you’re always at a disadvantage. That’s how the house is statistically guaranteed to make money when played at a large scale.
Roulette has red, black, and the green one.
A “fair coin” is a mathematical abstraction. There’s zero probability that actual coin flips are “fair”, in the mathematical sense. What I was expressing was the fact that this is way larger of an effect than I expected and, over time, this effect will change things that use coin flips.
Here is an alternative Piped link(s):
National Lampoon Vegas Vacation
Piped is a privacy-respecting open-source alternative frontend to YouTube.
I’m open-source; check me out at GitHub.
To be honest I think we have different cultural values here. The way I read this and the way you read it is clearly different. I’m disappointed by how little I had my expectations changed, while you had them moved more.
Where…?
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No! Bad treefrog.
If it “feels like” something, you’re probably fooling yourself.
Hard evidence. The easiest person to fool is yourself.
Edit: people, please don’t down vote treefrog. They are learning, and I am joking.
Be nice. This place is way toxic. I’m not sure how much more I can handle it.
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Jokes on me! I doubt most of my decisions and the logic that lead up to them!
Evidenced based research ftw, though.
If you’re still young, careful about too much imposter syndrome.
It took me until some reasonably extreme events for me to acknowledge that I was smart.
I’m being a bit facetious. It took me quite a while, and with the help of my best friend, to realize I am smart. I don’t like to say that sort of thing. I am smart when it comes to the things that I know well, but am clueless on so much else.
Exactly.
Just making sure.
I had a lot of trouble gathering that confidence as well until I got into industry.
🤗
I’m with you, i used to try influence what i wanted by catching it.
If i wanted what i had flipped from i caught it palm up and then revealed. If i wanted the opposite i caught it and then revealed it onto my other hand.
As i got older i wouldn’t let people catch the coin only let it hit the ground and bounce around.
I remember the opposite: heads always felt like “right way up” to us, but the result was almost always tails no matter who flipped it. To the extent that it still feels like the heads/tails percentage is the only positive version of the 50-50-90 rule, and I will never choose anything else.
Probably confirmation bias. But I wonder if the people in my family are wobblier than others.
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Now I wanna know if I can get better at landing on the same side on purpose…
Yeah… I had that thought for a second. Then I geeked out on the math and came to the same conclusion I had before.
Just as I won’t learn to play poker or count cards, I’m not learning and practicing this.
I’ve got other things to do with my limited life.
I suspect you can, if there is a bias when no effort is applied I suspect you can train to increase it. I can think of two main factors at play - how fast the coin is rotating and how long it remains in the air. Both of which are under your control and I suspect you can train to become more reliable for though it might take a lot of effort. Or you can just learn to do this in 10 mins. Who is going to know the difference? It is cheating either way.
Great minds think alike! I just referenced this video in another thread on this post, without having read your comment first!
Here is an alternative Piped link(s):
Or you can just learn to do this in 10 mins
Piped is a privacy-respecting open-source alternative frontend to YouTube.
I’m open-source; check me out at GitHub.
I have actually tried and practised that when I was a kid :-)
Humans inherently create patterns and routine in their actions. It’s why on roulette wheels they change the direction and the size of the ball regularly to prevent the spinners from pattern spinning.
They don’t all inherently choose to make it land on the up facing side. In fact, I believe this study is not even true. I call shenanigans.
I look forward to your article explaining how you used the scientific method to provide counter evidence to their study.
I’m going to do significantly more coin toss gambling now
