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The Coin Flip: A Fundamentally Unfair Proposition? (2009)

econ.ucsb.edu

1–10 of 31 posts

Re: The Coin Flip: A Fundamentally Unfair Proposition? (2009)

#4
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.

Re: The Coin Flip: A Fundamentally Unfair Proposition? (2009)

#5
post #3

My small take: http://www.win-vector.com/blog/2015/04/i-still-think-you-can...

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?

Re: The Coin Flip: A Fundamentally Unfair Proposition? (2009)

#6
post #4

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.

Re: The Coin Flip: A Fundamentally Unfair Proposition? (2009)

#7
"1% may not sound like a lot, but it's more than the typical casino edge in a game of blackjack or slots."

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%.

Re: The Coin Flip: A Fundamentally Unfair Proposition? (2009)

#8
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.

Re: The Coin Flip: A Fundamentally Unfair Proposition? (2009)

#9
post #8

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.

Re: The Coin Flip: A Fundamentally Unfair Proposition? (2009)

#10

"1% may not sound like a lot, but it's more than the typical casino edge in a game of blackjack or slots." 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%.

  Blackjack, video poker and some bets on craps are the only
  times in a casino where the house edge shrinks to below 1%.
Care to cite your source for this or are you a gaming industry insider?
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