probability

[RobcPettit]

Hi, Id like to use excel to work out the odds for the following.
using 13 cards, suit irrelevent, 2 through to ace. Ace high 2 low.
How do I calculate the odds. On betfair they have a hilo game card 1
or further upto card 11. At the start, before cards are turned they
have decimal odds of:
1 or further = 1.29, 2 or further =1.73, 3 or further= 2.33, 4 or
further
=3.1, 5 or further = 4.16, 6 or further =5.48 etc. How do they
calculate
these odds. When the first card is turned I can calculate the odds of
the next card bieng higher or lower, but not the odds for future
cards. Any ideas I know this may be a bit of topic here but Ive asked
every were.
Regards Robert

 

[James Silverton]

(e-mail address removed) wrote on Thu, 11 Oct 2007
12:24:51 -0700:

R> Hi, Id like to use excel to work out the odds for the
R> following. using 13 cards, suit irrelevent, 2 through to
R> ace. Ace high 2 low. How do I calculate the odds. On betfair
R> they have a hilo game card 1 or further upto card 11. At the
R> start, before cards are turned they have decimal odds of:
R> 1 or further = 1.29, 2 or further =1.73, 3 or further= 2.33,
R> 4 or further
R> =3.1, 5 or further = 4.16, 6 or further =5.48 etc. How do
R> they calculate
R> these odds. When the first card is turned I can calculate
R> the odds of the next card bieng higher or lower, but not the
R> odds for future cards. Any ideas I know this may be a bit of
R> topic here but Ive asked every were.
R> Regards Robert


Ultimately, odds calculation in Poker (?) might be done using
PERMUT and COMBIN but I don't have any idea what you want. I
guess I'd have to leave it to people who know what is a "hilo".

James Silverton
Potomac, Maryland

E-mail, with obvious alterations:
not.jim.silverton.at.verizon.not

 

[Gary''s Student]

Calculate it on the basis of what is left over:

Here is a simple example:

Say we draw a card. Say the card is a four. Say we do not replace the
card. We are going to draw another card and what to know what is the
probability the the second card will be :

1. less than the first
2. the same as the first
3. greater than the first

There are eight cards left lower than the first drawn card (four deuces &
four treys)
Therefore the probability that the next card is less than the first is 8/51

There are (always) three cards left the same as the first. Therefore the
probability the next card is the same is only 3/51

There are 40 cards left higher than the first. Therefore the probability
ofthe next card is higher than the first is 40/51

 

[RobcPettit]

Thankyou for your reply. HiLo is a game of 13 cards. 2 through to
ace, ace bieng high. On the turn of the first card you have to bet if
the next will be higher or lower. The variation on betfair is, on the
turn of the first card, betfair judges if the next card will be higher
or lower, and you are betting for or agains its judgement. So if they
think it will go higher on card 1 or further and betfair does, you
back at given odds. Which range from card 1 upto card 11. The diffulty
Im having is when the first card is dealt and betfair indicates its
position, I can calculate the first odds, but not for any of the
others. Throughout the game you can bet on 1 or further upto card 11.
as each card wins that option is eliminated, and the odds change. Hope
this makes sense.
Regards Robert

 

[RobcPettit]

Thankyou for your reply. In my game there are only 13 cards--
2,3,4,5,6,7,8,9,10,J,Q,K,A. before a card is drawn the odds worked
out for the game going 1 card or further, 2 cards or further up to
cars 11. When the first card is drawn, it is not replaced and the odds
are recalculated. I can see how to use your suggestion when I know the
first card, but not how to calculate further cards before there drawn.
Als not how to do it before any cards drawm.
Regards Robert