blonde poker forum

Inspired by the dice thread, see if you can work out this one.

If a game show host tosses a coin 100 times and gets heads every time, what are the chances that the 101st toss is heads?

a) >50%
b) 50%
c) <50%

none of the above obv.

Nobody would ever flip 101 heads.

so 0.000000000000000000000000000000000000%

Depends.

Is the show rigged, is it a double-headed coin, is it a big set up, what sort of crap game show is it where the host tosses a coin 100 times?  Is there nothing on the other side?

a)

Have you not watched ITV recently? It's only a matter of time

If we plot the results into an m by n matrix, one can simply deduce that there is no coin.

from the little that I saw that was the basic premise of red or black

You have seen him toss the coin in the air 100 times and it has landed on heads every time. You have seen the other side of the coin is indeed tails.

Given this information what can you intelligently conclude about the next toss?

I won't use Vaseline again, because it burns like hell afterwards?

its a bayesian thing I would imagine - some sort of probability of being rigged and 100 heads in a rows vs probability of not beig rigged and 100 heads in a row.

<50% and only because theoratically it could land on it's side... simples. The previous coin tosses have nothing to do with the next (assuming it's not rigged..100 heads in a row is unusual but obv not impossible)

Yeh I mean the probability that you get 100 heads in a row is 7.88860905 × 10-3, so unlikely in fact, that you'd be forced to conclude that the experiment is probably rigged or the coin is biased.

The interesting thing is, this logic implies that if you toss any coin once and it's heads, the chance of the 2nd toss being heads is very slightly more than 50%

The answer is c)

Or, you're overthinking it.

The answer is clearly a)

assuming your very long number is correct then what would you thing if the coin came down htttthhhththhhtthtttthhhhtthththttthhtththhhthhhtttththhththththhhthhththhhththtthhththtthhththhthth? the odds of this would also be 7.88860905 × 10-3, so unlikely in fact, that apparently you'd be forced to conclude that the experiment is probably rigged. or would you?

this is truly the worst game show ever btw. how do you win?

think you need a tails

it's not a gameshow. sorry, just an experiment with an audience.

gatso thats obv not the same thing. there's nothing unusual about you're sequence so you wouldn't question the reliability of the coin.

so what does the audience win?

If the game show host is a tosser then he is Vernon Kay.

Absolute epic reading fail by me

alex is correct. I take a coin from my pocket, flip it, and it lands on heads. I then do it again. For this second flip it is more likely to land on heads than tails.

The coin has a better understanding of the situation than most. He understands that a coin flip is a 50/50 and refuses to give a sucker an even chance shot and decides to wait for a better spot

c) Depends partly on the age of the coin too.

This.

Also your quoted probability is hilar wrong. You're suggesting that you will flip 100 heads in a row ~8 times in a thousand. It's 7.88 x 10^-31, or in the region of 8 in a billion trillion trillion.

lol, i missed the 1 off the end oops, fairly crucial typo. I just googled 0.5^100

0.5^100 = 7.88860905 × 10-31

yeah google is so smart. realised it was a typo after I googled it myself, still made me laugh that it went unnoticed tho

Why it's 50:50
Simples

cos there's a chance the coin is biased, therefore you should account that chance into the probability for the next flip. The only information you have about the coin is that it has just been tossed on shown heads. Therefore there's a chance its biased towards heads so >50% for the next flip.

there've been studies done that show that a coin that is heads up at the start of a flip are more likely to come down heads, same for tails. however because the general method of flipping involves catching it and then turning it over onto the back of our hands then it's actually more likely to come down tails if the last flip was heads (unless we turn it over first then the opposite is true)

this study becomes irrelevant if we let the coin fall to the ground as it all goes to shit when it starts bouncing around

Still not going to watch this game show.

Derron brown done flipping ten heads in a row ...took him ages apparently
cant find the clip on you tube though!

http://www.ecademy.com/node.php?id=134789

i agree totally with this too. it works and we had a guy in our pool team that always tossed the coin because he was pretty consistant at winning the toss for us.