Coin Flip Odds

[JoeyInCali]

I just tried flipping for 5 ahead.
Tails, head, tails, then heads showed up 6 in a row.

 

[M HOUSE]

What?

I just spent 30 minutes reading every post in this thread and I still can't make heads or tails of it.

BTW does anyone else out there know how to win betting on a coin flip by betting on BOTH heads and tails. It can be done but takes a big bankroll to begin with.

 

[Jigger]

.5 * .5 * .5 * .5 * .5 * .5 * .5 = .0078125

which also = 1/128

or you can say the probability (P) of something happening n times in a row, if each trial is independent and has the same probability, is P raised to the n power.

.5 ^ 7 = .0078125

Kelly

Thx Kelly that sounds right.

 

[Southpaw]

I just spent 30 minutes reading every post in this thread and I still can't make heads or tails of it.

BTW does anyone else out there know how to win betting on a coin flip by betting on BOTH heads and tails. It can be done but takes a big bankroll to begin with.

Heads I win, Tails you lose....

Southpaw

 

[M HOUSE]

Heads I win, Tails you lose....

Southpaw

Nice try, but no dice. Here's a clue. It has much more to do with how you manage your bets, and not so much to do with the actual outcome of the coin flip. But you are actually betting on both heads and tails every flip.

 

[JoeyInCali]

Nice try, but no dice. Here's a clue. It has much more to do with how you manage your bets, and not so much to do with the actual outcome of the coin flip. But you are actually betting on both heads and tails every flip.

Double your bet everytime you lose a flip.

 

[jay helfert]

After reading all of the post, I find it hard to believe that no one has come up with the only logically reason to call tails. If you notice, the head side of the coin is heavier than the tail side due to the extra silver it takes to make the head, therefore gravity comes into play during the flip and usually causes the coin to land head down. If you don't beleive me.....just ask FATBOY.

STFU!
Well, there's your answer. I wasn't planning on telling this to everybody but Jack did! When you see a coin spinning on a table top. it's about 11-10 or better it will land Tails up.

 

[jay helfert]

I just spent 30 minutes reading every post in this thread and I still can't make heads or tails of it.

BTW does anyone else out there know how to win betting on a coin flip by betting on BOTH heads and tails. It can be done but takes a big bankroll to begin with.

Try this, "Heads on the ground!" Can you fight?

 

[stuckart]

I've just realized that I need to accept my fate of losing the coin flips way more often than winning.

While playing Scotch in Vegas for the BCA we played 9 matches in a row and lost 8 of the 9 tosses. Most of which I let our opponents call. But we won all 9 matches and returned for the final 16 teams. Then I had singles the next morning and started out the same way. I played 6 matches and won only 1 toss again. Then on Sunday I played 5 more matches and managed to win 2 tosses, both of those matches I broke dry first and lost. Those were my 2 losses to finish in 97th place.

I have one helluva lag though, so I try and get all my opponents to lag for it instead, but people are pretty petty about it.

 

[PoolBum]

Thats incorrect. The different possibilities are:

BB
BG- Boy born first
GB- Girl born first
GG

ofcourse it cant be GG, so you are left with 3 different possible outcomes. 3-1

Southpaw

3 possible outcomes, 2 of which are not BB. Hence, 2-1. (2-1 also means 1 in 3, which is not the same as 3-1. Perhaps that's the reason for the confusion.)

 

[M HOUSE]

Double your bet everytime you lose a flip.

Your very close. The key is to double your bet only on the side you lost on while maintaining your original bet on the side you won on.

Lets say you start out betting $10.00 on both heads and tails. It comes up heads. Now you double your bet to $20.00 on tails and keep your bet at $10.00 on heads. This time it comes up tails. At this point you are even on your bet on heads and you are $10.00 AHEAD on your bet on tails. Now you return to your original bets of $10.00 on both heads and tails.

If you follow this pattern you will always win. But remember, you will need a large bankroll to start with for those times when the flip comes up the same way a number of times in a row.

 

[jimmyg]

The odds that they are both boys are 2 to 1.

We already have two Givens: 1) one child is a boy. 2) the genetic odds of having either a boy or girl are equal, 50/50.

The only unknown is the sex of the second child, and the odds are one in two (50/50) that it will be a boy.

So we are actually only betting whether the second child is a boy or a girl, the additional information is nothing more than intellectual interference, and the relevant odds do not deviate from 50/50.

If the question was asked without knowing that the first child is a boy, then it would become more complicated.

Jim

 

[Patrick Johnson]

Jaden:
I don't blame you if you can't follow this, it is high level philosophy

LOL.

You're thinking too small. Think about all the other coins being flipped in the world today, throughout past history and into the future. Odds are that all of them taken together will come up heads very nearly half the time, but any one of them (yours, for instance) could come up tails 100 percent of the time and still not noticably tilt the overall balance of results. You can't use the overall average to predict the results of any one coin, and you certainly can't use it to predict the results of a few flips of one coin.

In other words, you have to include a sufficiently large number of trials in order to have confidence in the balanced results. And with a sufficiently large number of trials, the imbalance created by a "streak" of heads or tails does not need to be counter-balanced by an opposite streak. Even if the coins land exactly half heads and half tails from that moment forward, the imbalance gets progressively smaller and smaller as a percentage of the total number of trials - in the long run the 50/50 probability is proved regardless.

pj
chgo

 

[PETARD]

You Sir Should Never Gamble

 

[Patrick Johnson]

.5 * .5 * .5 * .5 * .5 * .5 * .5 = .0078125

which also = 1/128

or you can say the probability (P) of something happening n times in a row, if each trial is independent and has the same probability, is P raised to the n power.

.5 ^ 7 = .0078125

Kelly

All that fancy-looking math simply means there are 128 possible outcomes when you flip a coin 7 times, and only one of them is all heads. Below is a simple graphical illustration - each possibility is a branch from the top level to one of the bottom level outcomes. "All heads" is one branch among 128 possible branches.

But be careful when you say "the probability of something happening n times in a row". That could mean heads or tails, which are two distinct possibilities with a combined probability of 2/128. To be clear you need to say "the probability of one specified outcome (of following one specific branch among all the possible branches) is 1/128."

pj
chgo

http://forums.azbilliards.com/attachment.php?attachmentid=68397&stc=1&d=1212263269

 

[androd]

Yeah, I'm fully aware about the possibilities regardless of previous outcomes. It's a bit like how the casinos made a killing at roulette when they started having electronic displays showing the past dozen or so numbers/colors. When, for example, red was hit 5+ times in a row people would notice and bet en masse on black... only to have another red show up. Such is the logic we fool ourselves into.

At this point it's just become funny. We kept laughing each time I lost. I'm sure the table adjacent thought we were crazy.... they may have been right.

being a gambler i'd advise betting on the streak(red) as you can only lose one bet , if you bet black you can lose an unlimited number. most people usually do this wrong. human nature

 

[androd]

STFU!
Well, there's your answer. I wasn't planning on telling this to everybody but Jack did! When you see a coin spinning on a table top. it's about 11-10 or better it will land Tails up.

if its a new penny you can lay 3to2 probably 8to5 if its being spun. i'm sure, i've done it.

 

[MVPCues]

All that fancy-looking math simply means there are 128 possible outcomes when you flip a coin 7 times, and only one of them is all heads. Below is a simple graphical illustration - each possibility is a branch from the top level to one of the bottom level outcomes. "All heads" is one branch among 128 possible branches.

But be careful when you say "the probability of something happening n times in a row". That could mean heads or tails, which are two distinct possibilities with a combined probability of 2/128. To be clear you need to say "the probability of one specified outcome (of following one specific branch among all the possible branches) is 1/128."

pj
chgo

http://forums.azbilliards.com/attachment.php?attachmentid=68397&stc=1&d=1212263269

LOL That wasn't exactly fancy math.

Yeah, you stated it more accurately, but I don't think anyone was confused regarding my implying the generic "something happening" was the one specified event of heads coming up on the flip. That was what the question was about.

Kelly

 

[av84fun]

Double your bet everytime you lose a flip.

That's called a Martingale or sometimes Chinese Doubles system and it is seriously flawed.

You bet $5 and you lose.

Your next bet is $10. If you lose:
Your next bet is $20. If you lose:
Your next bet is $40. If you lose:
Your next bet is $80. If you lose:
Your next bet is $160. If you lose:
Your next bet is $320. If you lose:
Your next bet is $640

In this system, you become progressively dumber. For example, on the last bet, you are risking $640 to win $5

Such streaks are not at all uncommon.

Be careful out there.
(-:

Jim

 

[Patrick Johnson]

LOL That wasn't exactly fancy math.

Remember your audience.

Yeah, you stated it more accurately, but I don't think anyone was confused regarding my implying the generic "something happening" was the one specified event of heads coming up on the flip. That was what the question was about.

Kelly

I agree. In fact, I think my pedantry probably confused more people than it helped.

pj
chgo