Exact declarer and dummy
Enter South and North as complete visible hands, then let the app remove and restore cards as play advances or is undone.
Bridge SolverProbabilistic declarer play
Single-Dummy Bridge Analysis
Evaluate the next declarer-play decision without pretending the hidden hands are known. Bridge Solver generates defender layouts from your constraints, compares the legal cards and reports the aggregate result.
Analyses require a Bridge Solver account.North / dummy♠ A 9♥ Q 8
W7♣N2♣
South / declarer♣ A J 6♦ K T
| Play | Make | Avg tricks | IMP vs best |
|---|---|---|---|
| A♣ | 61.7% | 9.18 | 0.00 |
| J♣ | 56.4% | 8.91 | -0.23 |
Workflow
How Single Dummy works
The current analyzer follows a hand trick by trick and answers one declarer-side decision at a time.
- 01
Set the contract
Choose the level, strain, doubling and vulnerability. South remains declarer and North remains dummy in the current workflow.
- 02
Enter the visible hands
Provide South and North exactly, using the remaining cards when analysis begins after earlier tricks.
- 03
Describe hidden defenders
Give East and West HCP, suit-length and hand-filter constraints that reflect the auction and observed play.
- 04
Analyze and continue
Compare the legal plays, select or record a card, enter defender cards from the remaining pool and repeat on a later trick.
Current capabilities
What the analyzer does today
This is a functional analysis workspace, not a waitlist or a disguised double-dummy deal solver.
Constrained hidden layouts
Model East and West with point ranges, suit lengths and custom bidding or shape expressions.
Legal-play comparison
Candidate cards respect the suit led and are tested over the same generated defender layouts.
Three scoring objectives
Rank decisions for IMPs, matchpoints/raw score or contract make percentage.
Decision metrics
Compare contract success, average tricks, average score, IMP loss from best, matchpoint percentage and confidence intervals where available.
Trick-by-trick position entry
Click visible cards, choose defender cards from the remaining deck, undo one card or rewind to a previous trick.
Concept
Single dummy versus double dummy
The word single dummy describes the information problem, not merely the number of hands typed into the form.
Double dummy answers a fully known position
A double-dummy solver sees North, East, South and West. It can find the maximum tricks for each side because there is no uncertainty about breaks, locations or defensive resources. That is ideal for establishing the technical result on a completed deal and for solving each generated world consistently.
Single dummy keeps the hidden hands uncertain
At the table, declarer sees only the declaring hand, dummy, the auction and cards already played. Single Dummy creates many East- West layouts compatible with that information. A candidate play is evaluated in each layout, and the analyzer summarizes its expected performance across the sample rather than selecting a line for the one hidden deal it can secretly see.
Example
Analyze the current notrump decision
South declares 3NT. Dummy is visible, the defense has led clubs and declarer must decide whether to win now, duck or choose between equivalent-looking honors.
Use auction and play information
Enter the remaining South and North cards. If West opened or overcalled, describe the promised range and suit. Cards already played are removed from every generated layout. The defender card picker shows only cards not visible in declarer, dummy or the play history, reducing entry mistakes as the hand progresses.
Run the analysis when South or North is to play. The candidate table can show that winning the ace has the highest make percentage while ducking produces a better raw score in a different scoring mode. After choosing a line, record the observed cards and analyze again at the next genuine decision rather than assuming the rest of the hand is automatically settled.
Interpretation
Read probability and consequence together
Contract success percentage measures how often the target is made after each candidate. Average tricks and score distinguish plays that make equally often but produce different overtricks or undertricks. IMP versus best and matchpoint percentage translate those score distributions into the selected objective. Confidence intervals and equivalence flags help prevent tiny sample noise from being presented as a meaningful edge.
Also inspect the generation information. Five hundred layouts can be useful for a quick direction; a larger run gives a steadier estimate but takes more work. Rare East-West constraints can lower the acceptance rate, and a result based on fewer generated worlds should be read accordingly.
Runtime expectations
- Available targets range from 500 to 10,000 hidden layouts.
- More legal candidate cards require more evaluations.
- Narrow defender filters increase generation attempts.
- Jobs can wait behind other analysis work on the server.
- No fixed completion time is promised for a given deal count.
Limitations
What this analysis does not know
The generated defenders follow the constraints you enter; Bridge Solver does not infer a full probabilistic bidding model from an auction. Double-dummy continuation inside each world also assumes best defense with complete information. It does not model falsecards, table tempo, signaling agreements, an opponent’s skill or the declarer’s ability to discover the layout gradually.
Those limits do not make the comparison useless. They define the question it answers: among the legal cards now, which performs best over the hidden layouts you consider plausible when every world is continued consistently? Use that as technical evidence alongside inference and practical play judgment.
Questions
Single-dummy bridge analyzer FAQ
Is the Single Dummy analyzer available now?
Yes. Signed-in users can open Single Dummy, enter South as declarer and North as dummy, describe the hidden defenders, play observed cards through the hand and analyze a declarer-side decision.
What is the difference between single dummy and double dummy?
Double dummy solves a deal with all four hands visible. Single-dummy analysis generates plausible hidden defender hands, evaluates each legal play over those layouts and aggregates the outcomes available under incomplete information.
Does it automatically play the whole hand?
No. The current workflow recommends the best card at the present South or North decision. You record the cards actually played, move to later tricks and run another analysis when the declarer side is next to act.
Why can Single Dummy take longer than a deal solve?
One fully known deal needs one double-dummy position. Single Dummy must generate many hidden layouts and evaluate multiple legal candidate cards over that sample, so the work grows with both deal count and candidate count.
Can I analyze a defender’s card?
The current analyzer records defender cards from the unseen-card picker but runs recommendations only when South or North is to play. It does not currently recommend East or West’s defensive play.
Keep exploring
Related bridge analysis tools
Run your own analysis
Analyze the next play under uncertainty
Enter declarer, dummy and the hidden-hand constraints, then compare the legal cards at the current decision.