Help With Probability

[ukanonymous]

Help with probability

Say you are playing a gambling game which is 0.5 To play

The prizes are as follows:
52% lose
1% chance to win 0.52
1% chance to win 0.7
1% chance to win 0.72
45% chance to win 1.0


After 1000 games How much will you have spent and how much are you likely to win and how do you predict/ calculate how much you will win?

[jim360]

My mistake, I'm sorry.

But since your arithmetic -- and everyone else's -- is consistently going against the idea that you should break even, it is clear that the idea of breaking even is wrong. The reason is, as has been said, because your winnings aren't really 52 but 2, since your original stakes were 50 to start with, win or lose. If you lose your stake half the time, then playing 20 times your initial stake is 1000 and your expected winnings are 520 < 1000.

[Old_Geezer]

Looks ok to me.

stake (non-refundable) £0.50
number of bets 1000
total staked £500.00

50% 500 £0 £0
1% 10 £0.52 £5.2
3% 30 £0.70 £21
1% 10 £0.72 £7.2
45% 450 £1 £450
100% Total £483.4

[Old_Geezer]

Strange choice of win values though.

[ukanonymous]

If its 50% you theoretically on average break even if you leave at the right time. So when we are averaging out 1000 plays you should get the value you just quoted 520 < 1000 But I got prizes after 1000 games is 483.4

So I am making a mistake surely

[ukanonymous]

Jim I could probably understand it more with mathematics if you have time :)

[fiction-factory]

I think it's just a matter of rounding. 520 less than 1000 is 480 which is close to your figure of £483.40.

[ukanonymous]

OG thanks for that. Thats what I get too. But I some how think its wrong as what happens to the 16.6?

I think I am going to reverse the probabilities from the game perspective and see what happens

[jim360]

But now you are confusing different games, though -- and also misusing "break even".

The game in which you get a payoff of 483.4 is the one where there are four different winning scenarios from page 1 -- and then that was a payoff of 483.4 from an initial stake of 500, rather than 1000.

The game in with you get a payoff of 520 is -- here -- one in which your initial stake of 50 wins 52 half the time and otherwise wins nothing.

"Breaking even" is not when you win half the time and lose half the time, but when the money you can expect to win back exactly matches the total amount you have staked. It does not mean winning half the time and losing half the time.

[fiction-factory]

What happens to the £16.60?
That's the organiser's expected profit per 1000 plays- so it goes in your pocket

[Old_Geezer]

Precisely ff.
What the punter loses the organiser gains.

[ukanonymous]

Aghh too much coffeee today..

So this is how I will set the game:

Say you are playing a gambling game which is 0.5 To play

The prizes are as follows:
51% lose
1% chance to win 0.52
2% chance to win 0.7
1% chance to win 0.72
45% chance to win 1.0


The Game will profit by 23.4 which is what %?

So basically what % does the table take? I mean this in terms of.. The house has a 1% edge what does this mean? In the game in this post you have a 49% chance to win does that mean the game has a 1% edge?

I am new to this gambling and probabilities and I am making a gambling game and it is really driving me up the wall.

[fiction-factory]

£23.40 out of £500 is the same as £46.60 out of £1000 so I would say that's a profit of 4.66%

[ukanonymous]

So when they say 1% edge they mean profit % of the game? Or % that the game wins?

[ukanonymous]

So when they say 1% edge they mean profit % of the game? Or % in terms of PROBABILITY that the game wins?

[fiction-factory]

But I agree with O_G that the win values still look odd.
I can't see why you want to mess around with a 2p win or why there is a need for separate prizes of both 20p and 22p. Unless the aim is to confuse the customer.

[fiction-factory]

Soorry, I'm no gambler so I don't know what 'edge' means

[Old_Geezer]

Long term it is the same thing. The actual profit from a session is unknown in advance, but the probably shows what you expect.

[ukanonymous]

Ah sorry no this is all in Bitcoin. 0.02 Bitcoin is around 3 pounds at the moment

[Old_Geezer]

An edge means that card you have up your sleeve.

[fiction-factory]

The percentages will be the same, regardless of whether it's pounds, dollars or bit coins.