Dear Ed & Peter,
The question is: I need a program to calculate a possibility if (for example) South has 11-21 with five spades, what is the chance that West has 15-17 balanced?
Do you know any free programs?
Reply Ed Hoogenkamp (South) and Peter van der Linden (North)
We do not know any such program. That is hardly surprising, since we do know very little of this subject... In fact our ignorance is of such a magnitude, that we haven't been able to insult each other with it... a sad draw you could say.
However, by publishing your question here we hope to get reactions of people who do!
So: anyone who reads this and knows of such a program, please let us know here
Un saludo desde Barcelona and en hils fra Orkanger
Reaction Charles Gray 12 April 2010
There is no simple program for calculating bridge odds. Finding a particular shape is the easiest. It involves combinations of A things taken B at a time. That is A factorial divided by B factorial and divided by (A-B) factorial for each of the suits, taking the product of these numbers and dividing the result by 52 taken 13 at a time.
You think this is a lot of calculating? When you add high card points into the equation, the complexity is compounded. I did manage to find a web site that provides some of these odds. I copied the data and saved the information on my computer. I don\'t seem to have a reference to the site anymore. I suggest you search for 'bridge odds'. It may seem surprising to you but the shape of your hand influences the probability that you will have a certain number of high card points. With a 2-suited hand, the most points you can have is 20 while with 4-3-3-3 shape you can have as many as 37 high card points. I hope this helps.
Greetings, Charles Gray
Reaction Jeremy Williams 18 April 2010
A correspondent asked if there is a program to calculate bridge odds. (The example given was West having a strong notrump when South has a Standard 1♠
Exact calculation of such odds is nontrivial. There is, however, a program that can do simulations of any situation you can define. The program is Thomas Andrews' "Deal", click here
to take a look.
'Deal' generates random hands. The interface allows the user to make requirements about any of the hands (e.g., suit lengths, HCP, controls). In addition to generating a file with the hands (or a representative sampling of them), 'Deal' can do double-dummy analysis and statistical reporting.
In the example in question, it is easy to tell 'Deal' to generate ten million (for example) hands where South has 12-21 HCP and 5+
spades, then calculate what fraction of these hands West will have 15-17 HCP and whatever distribution requirements you want for the notrump bid.
You can even write your own custom definition of what constitutes a good enough stopper for West to overcall 1NT. The program has a custom scripting interface overlaid on top of Tcl. It is fairly easy to learn and fairly intuitive — and decently documented, too.
Reaction Eric Basalou 13 May 2010
I created a program to calculate all sorts of bridge odds. It is very effective but its language is French (as well as that of the associated help file) and I don't plan to translate it into English!
I offer it for free, as is, to the bridge community, as a zip installation file.