# BBO Discussion Forums: software to calculate the odds of making a contract? - BBO Discussion Forums

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## software to calculate the odds of making a contract?

### #1mkrawczyk

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Posted 2019-May-22, 04:40

dear all,
I have, say, a 100 bridge deals and I want to calculate for each of them the probability of making different contracts (several per deal, say 3NT by N, 4H by S, 2H by S...), assuming everyone plays correctly and assuming that you only know the declarer's and dummy's hand. Say, if the declarer wins if and only if the king of spades is on his/her left hand side, the probability will be 50% and so on. Do you know of any software that would allow me to obtain these probabilities? Ideally, with some non-graphical interface so that we could automate data entry.
michal
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### #2etha

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Posted 2019-May-22, 07:10

BBO has this which will do what you want except for the automate part. http://dealergib1.br...aler/dealer.php

Also assuming by correctly you mean double dummy.

The actual program deal is available and is even free and you can if you are a programmer make it do all the things you want including the automation but you would have to write some code to do it.

If you want it not double dummy then the only way I know of is to purchase Jack. You can make it play the 100 deals you want single dummy and/or par score the hands. Its declarer play is good enough to make this worth while, its defence is only the level of a decent club player though I would estimate.
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### #3steve2005

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Posted 2019-May-22, 08:47

I think poster is asking for single dummy solutions.
Sarcasm is a state of mind
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### #4johnu

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Posted 2019-May-22, 12:55

steve2005, on 2019-May-22, 08:47, said:

I think poster is asking for single dummy solutions.

Then the answer would be zero options because nobody has programmed a viable single dummy solver.
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### #5johnu

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Posted 2019-May-22, 13:00

I use Dealmaster Pro. It will calculate the double dummy results for up to 4 contracts at the same time. There is no input facility for batch processing multiple scenarios consecutively. What exactly are you trying to do?
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### #6mamimami

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Posted 2019-May-23, 16:56

For single-dummy analysis, you can also use Jack http://www.jackbridge.com/eindex.htm
It is kind of limited but it works as follows:
Deal two hands manually with deal editor, and to be more realistic, optionally enter the bidding sequence.
Then generate as many as hands as you like.
Save them.
Open them and before selecting and loading any deals from list of saved deals (you generated as described above), select all and "make double dummy analysis".
Now you can save the analyzed deals.
Two options from here:
-Manually inspect each deal, visually checking every possible deal
-Programmatically analyze duble-dummy analyzed saved PBN file containing the generated deals
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### #7thepossum

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Posted 2019-May-23, 19:56

bcalc by Piotr Beling has double and single dummy solvers. I believe it is impossible to calculate single dummy probabilities well but his software includes a number of simulation options and programmable constraints and a script language. It also includes bdeal which allows you to run simulations of many hands

Of course single dummy simulation uses double dummy with random samples of hands much like GiB I imagine

http://bcalc.w8.pl/

I also think there needs to be a better approach to double dummy simulations. I think most calculate a mean number of tricks when in fact the distributions are more complex and different statistics and distributions may be more appropriate. However you can write scripts to do the more sophisticated analysis - eg probability of each number of tricks and work out strategies for different situations

For example MPs and IMPs would have different goals etc

Its quite run experimenting with simulations and scripts. But you would need a lot of time to produce a really good simulator and player and its never going match good humans.

Also real bridge is not double dummy. But its worth a look

Also you need to consider that 1) most contracts are unreachable using most sensible bidding systems - so there is only a subset of candidates and 2) everything from bidding, leads, play etc depends on different players knowledge, competence, style, mood, error distributions.

Its impossible to say that there is a 75% chance of making 3NT, say. You can get a rough idea on a distribution with certain assumptions and playing a certain way. But the level of uncertainty and lack of information and how real players deal with information is just massively complex.....
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### #8etha

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Posted 2019-May-24, 08:25

mamimami, on 2019-May-23, 16:56, said:

For single-dummy analysis, you can also use Jack http://www.jackbridge.com/eindex.htm
It is kind of limited but it works as follows:
Deal two hands manually with deal editor, and to be more realistic, optionally enter the bidding sequence.
Then generate as many as hands as you like.
Save them.
Open them and before selecting and loading any deals from list of saved deals (you generated as described above), select all and "make double dummy analysis".
Now you can save the analyzed deals.
Two options from here:
-Manually inspect each deal, visually checking every possible deal
-Programmatically analyze duble-dummy analyzed saved PBN file containing the generated deals

Or for actual single dummy analysis press create tournament with replay by jack
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### #9johnu

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Posted 2019-May-24, 23:51

Just to clarify what double dummy analysis means for robot play,

Suppose you have North/South hands that you want to analyze. You randomly deal (e.g. Monte Carlo simulation, or start with specific East/West hands) a specified number of East/West hands, possibly with qualifications, and then each deal is analyzed double dummy. What that means is that the opening leader always makes the best possible lead, and both declarer and defenders make each play knowing the location of all 52 cards. So there are never any misguessed finesses, offside honors are dropped if possible, all suit splits are known. The best result possible by best play for both sides is the end result for any specific hand.

So even though you may only have dummy and declarer's hands, you aren't getting a single dummy result, you are getting a dummy dummy result.
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### #10etha

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Posted 2019-May-25, 05:32

Just to clarify what single dummy play means. If you take the two known hands and deal the rest and then give them to 4 people to play and score the result that is single dummy. Similarly if you give the 4 hands to robots that play the hands you get a single dummy result. If you par score the deal or play the hands dbl dummy then you get a dbl dummy result.
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