# Talk:Coin flipping

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WikiProject Mathematics (Rated B-class, Mid-importance)
This article is within the scope of WikiProject Mathematics, a collaborative effort to improve the coverage of Mathematics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.
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Field: Probability and statistics

## comment

Just noticed that this page on coin flipping looks a lot like this other one:

http://www.informationblast.com/Coin_flipping.html

That would be because it has copied WP - see lower down that page. Charles Matthews 12:57, 30 Nov 2004 (UTC)

Am I the only person in the world who tosses guitar picks instead of coins? A pick whose faces are physically equal is far less likely to be biased than a coin . --Army1987 12:14, 30 Nov 2004 (UTC)

Probably. The bias of the coin is, to my understanding, fairly small. Moreover, most people don't know what the bias is, so it's just as likely to help the caller as hurt them. I was almost a little surprised this article doesn't have info on biases for commonly flipped coins, given the detail of some of the other information. It seems like it must be pretty obscure.
According to the work by Persi Diaconis the bias is in favor of the side of the coin that is up before the flip. If the flipper is not careful about the starting configuration (for example pulling the coin out of his pocket without looking it), then the bias is greatly reduced, which I'd argue is a more realistic setting in most real-world uses of coin flipping then assuming the starting configuration is fixed. — Preceding unsigned comment added by 24.4.207.28 (talk) 13:09, 29 May 2011 (UTC)

## Oh, my God...

You did that much math to decipher a coin toss???

You all scare me. :-) --Penta 07:29, 1 Mar 2005 (UTC)

## Cut section

I append the mathematical section, cut by User:Grick recently. Charles Matthews 10:48, 3 Mar 2005 (UTC)

## Checking if a coin is biased

I am making what was warehoused here a page in its own right. Charles Matthews 11:35, 20 Mar 2005 (UTC)

## Coin flipping in fiction

In the section under the same hdg, we have

Conversely, the 1972 movie of Graham Greene's novel Travels with my Aunt ends with a coin toss that will decide the future of one of the characters. The movie ends with the coin in mid-air.

and someone commented within the article

[Someone familiar with Greene's novel or the stage version should edit this to say whether they end similarly.]

Indeed they should, but the solicitation does not belong in the article!
--Jerzy (t) 05:29, 2005 Mar 24 (UTC)

Also the movie The Sentinal used coin tosses. 203.87.45.25 05:34, 19 January 2007 (UTC)

One of Practchet's Disk World novels features one of the witches calling "edge" during a coin toss and winning. Jon 19:24, 22 February 2007 (UTC)

## Deciding among three outcomes

What would be the quickest way to use a coin to decide between three choices? Off the top of my head, I could see flipping the coin in sets of three flips, where you go until only one choice comes up heads. What else? --Duozmo 21:23, 25 December 2005 (UTC)

Flip the coin in sets of three. If they all land on the same side, repeat, else, the single result wins. Example: THT - no. 2 wins with H. Bogfjellmo 18:40, 4 January 2006 (UTC)

Just flip it twice - one flip eliminates one option, the next splits the remaining two. The outcome is random so if it's simply a matter of choosing one you shouldn't need anything fancy. Richard001 19:25, 28 January 2007 (UTC)
I think what they meant was to decide between three choices giving each an equal weight. If you flip a coin only twice, eliminating one option each time, you are favoring the choice that is not involved in the first coin-toss (it essentially gets a bye). Bogfjellmo has it right. DC NemesisTalk 05:20, 7 April 2007 (UTC)
Alternatively, flip the coin in sets of two until something other than TT comes up. Let the first choice correspond to HH, the second to HT, and the third to TH. On the other hand, the sets-of-three approach above works even with a biased coin (because the probability of THT is the same as the probability of HTT or TTH, since the coin has no "memory"). --66.57.63.226 (talk) 21:51, 7 May 2008 (UTC)

## Coin flipping in fiction - redux

I have made beau coup cosmetic improvements to this section (wikilinks and grammar) ... it started innocently enough with finding and adding a link to The Twilight Zone episode, but then my OCD kicked in and it became a Project ... I'd better quit now before I read any of the other sections and end up spending hours on this one article! :-) —68.239.79.82 05:16, 22 May 2007 (UTC)

## Telecommunications?

Can someone explain why this should be here? It seems really out of place and complicated. It's not really coin-flipping at all. It's just a way to end a dispute.
Jay42 22:32, 13 July 2007 (UTC)

## Significant coin flips in history

I can't believe there is a section about fictional coin flips, but not in reality. Geez! Someone should start one.

Gregbard 05:13, 31 July 2007 (UTC)

## History of Coin Flipping

What does Jonah and the whale have to do with the history of coin flipping, if the blurb itself says it has nothing to do with coin flipping? If this is an article on random dispute resolutions, that's one thing, but if it has nothing to do with the history of coin flipping, it seems like it should be removed.

The sailors on the beleagured ship cast lots (something like tossing a coin, in terms of leaving a decision up to a fate determined by the use of inanimate indicator objects) and Jonah was indicated by the lots as being the person whose fault (trying to escape God's will) had caused the storm that threatened the ship's (and its passengers') demise. Once he was tossed overboard the seas calmed, proving the decision to have been correct.96.237.177.108 (talk) 12:21, 16 February 2011 (UTC)

## Coin flipping in fiction: Keep?

User: 83.31.210.1 deleted the entire "coin flipping in fiction" section. This has evidently been part of this article for a long time and has received multiple contributions from multiple users. It's my sense that this section is interesting, useful, and shouldn't be deleted wholesale without discussion first. I've put back the section pending any contrary consensus that may be developed here. —Preceding unsigned comment added by Arxiloxos (talkcontribs) 13:40, 24 July 2008 (UTC)

## The process of coin flipping

This section is admirably detailed... but sort of absurd. This whole section could be replaced by two little sketches or photos. 76.201.147.205 (talk) 04:27, 10 August 2008 (UTC)

## Option 3?

Should there be a mention of a coin landing on its edge? I've seen it happen, in fact I have it photographed with my cellphone. It hit the ground, bounced off, started spinning on its edge and when it stopped spinning it didn't fall to either side, it just stayed on the edge. —Preceding unsigned comment added by 86.61.67.169 (talk) 01:15, 3 September 2008 (UTC)