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.
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.