They aren't guessing heads or tails, they give odds for each event. It's more like eyeballing a thousand coins to guess how fair they are, and then flipping each one just once.
Some are weighted to be 99% heads, others are 10% heads etc.
You could have 1,000,000 people guess random percentages for each coin, but suppose 10 of the coins are weighted 100% heads. To guess within 25% of the true value for all 10 of those coins would be roughly 1 in a million.
So a lucky guy guesses within 25% for all 10, he'd have another 990 coins he's being judged on.
It is precisely in unregulated markets I would want to use a ride shape app else they'd try to scam you on the price. Multiple times I've had drivers attempt to triple the agreed to price, or I'd have to haggle them down before the ride etc. This was over 20 years ago and Uber and the like did away with all that.
I suspect the anxiety of being unable to forget things has an inherent selection bias. You will only stress over the things you can't forget, the things you have forgotten you won't stress over...
Generally claims of eidetic memories are overstated, doubly for older claims, but Nigel Richards memorized a French dictionary in 9 weeks, over 6k words a day, x2 including the alphagram.
I consider myself to have a decent memory, but that is 200x what I'd think myself capable of, assuming I want to retain it all at the end of the 9 weeks.
There’s also one specifically for God - 祂, and one for animal - 牠, the first one you can see frequently in Chinese bibles or churches, the latter is rarely used.
Some are weighted to be 99% heads, others are 10% heads etc.
You could have 1,000,000 people guess random percentages for each coin, but suppose 10 of the coins are weighted 100% heads. To guess within 25% of the true value for all 10 of those coins would be roughly 1 in a million.
So a lucky guy guesses within 25% for all 10, he'd have another 990 coins he's being judged on.