That one person doesn't know it doesn't mean it's not common knowledge.
That said, the edge is not always below 1%. It varies based on the rules. Some games don't allow a surrender, for instance, which changes the edge pretty drastically.
No casino in the states of NV, CA or LA has ever informed me nor have I seen other patrons be duly made aware of the 2%-15% for the slots nor the 1% for Blackjack, Video poker or Craps.
In Nevada, I don't see any stipulation they're even required to, by the Nevada Gaming Commission. [1]
[1] LICENSING AND CONTROL OF GAMING - GENERAL PROVISIONS
Neither I nor anyone has said that they are required to make you aware, let alone "duly" so.
For instance, it makes good business sense for a casino to advertise their 94.64% slot return since they still have an edge. You don't have to be an industry insider or close to it to learn this information, as you implied.
It says it right on the card on the table that explains the min/max bets (in Aus at least). Also, it's basic stats which can be applied depending the house rules.
A commenter explains that the most interesting claim (51% bias) is not explained correctly in the article. Humans flipping a coin add a bit of precession (spin) that biasses the toss. The "odd/even time in the air" analysis is incorrect -- that only matters if it is possible to stop the coin before the first flip.
Yep. To see this, consider a coin flipped into the air so that it's tilted 45 degrees with the floor and spinning only around the vertical axis. To a casual observer it will appear as if the coin is tumbling but in fact one side faces up 100% of the time.
Ahh right. People I know usually call after the flipper catches and covers it. So they would have to have some technique for flipping it as they raise their hand to reveal the coin. Difficult but I guess not impossible.
This video from Numberphile goes in depth about this: https://www.youtube.com/watch?v=Obg7JPd6cmw . The guy talking, is Persi Diaconis, is the main author of the paper this article is based upon.
If the coin has a substantial thickness, is it still accepted as a coin? I think not. How much density differential do you need to generate a 1% bias in a coin no thicker than any existing UN member currency?
The paper ends with "The caveats and analysis also point to the following conclusion: For tossed coins, the
classical assumptions of independence with probability 1/2 are pretty solid."
I think this link botches the explanation for 51%. 51% is because of precession, as explained in the paper[1]. With enough precession the coin will always come up heads if it starts out heads. That's how magicians control coin tosses.
He tries to describe it in terms of HTHTHT. Coins do not have memory. They don't know if they've previously flipped 3 times, 4 times, or 1e308 times. If you draw from [HTHTHT..HT] randomly, you'll get 50% heads and 50% tails. Change that to [THTHTH..TH] and the answer is the same.
With precession the answer changes because it stays in the initial state longer. As the paper points our "Keller showed that in the limit of large initial velocity and largerate of spin, a vigorous flip, caught in the hand without bouncing, lands heads half the time." Keller assumed no precession.
edit: I just saw that in the comments they point this flaw out. It gets hand waved away by the author as a "oversimplification" that he made. My opinion is that it is okay to simplify, but not to the point of being wrong. The explanation is not how probability works, at all.
The most interesting part to me was this
"A coin will land on its edge around 1 in 6000 throws, creating a flipistic singularity." (https://en.wikipedia.org/wiki/Flipism)
I assume that was as the result of using the tossing machine, but I really thought it would not have been that frequent.
I have this happen a lot when tossing on wooden floors with a gap between the boards - basically the coin gets stuck in the gap. My brother and I got quite good at deliberately doing this.
I have never had it happen on a flat surface and I must have tossed 10,000 of coins in my youth.
I once attempted to hand a quarter to a convenience store clerk. Somehow we dropped it during the exchange. The coin rolled about 8 feet and went thru a tiny gap between two large cardboard boxes on the floor.
I'm sure I could have stood there for an hour attempting to drop a coin onto the floor and have it roll into that gap, and I would have failed.
I had a similar situation in which a coin I tossed managed to end up stuck in a small gap in the celling. I remember having to get up on a chair on top of a table (I must have been under 10 at the time) to get it out. Good times :)
If the odds of landing on an edge are 1 in 6000, it's not particularly unbelievable that you wouldn't have seen it in 10,000 tries. The odds of not seeing it are about 18%.
The house edge for slots games is anywhere from 2% to 15%+ and is one of the worst bets you can make in the casino.
Blackjack, video poker and some bets on craps are the only times in a casino where the house edge shrinks to below 1%.