The Bridge Hand Simulator
Some bidding and lead decisions depend on cards nobody can see, and a single deal proves little either way. The hand simulator deals a large batch of hands that fit the situation you describe, works out each one with perfect play and turns the results into statistics, so a choice between two contracts or two leads rests on many deals instead of one.
What the hand simulator does
The BridgeTricks hand simulator, in the Bridge Lab, deals between 1,000 and 20,000 hands that match your constraints, analyzes every one double dummy and reports the results as charts and tables. It runs two kinds of simulation.
- A contract simulation shows how often each contract makes, the average number of tricks and how the hands dealt spread across your constraints, for up to five contracts in one run.
- A lead simulation takes one contract and ranks all 13 possible opening leads by the average tricks they give declarer, with figures in IMPs per board and in matchpoints.
Double dummy means each deal is played as if all four players could see every card, with best play from both sides. The simulator needs a free account, because every run is paid in credits.
How to simulate bridge hands
- 1.Open the simulator and choose the simulation type, Contract Simulation or Lead Simulation.
- 2.Describe the hands. For each player pick Cards mode to enter exact cards, or Constraints mode to set shape, suit lengths, card pools, controls, honors and HCP. You can mix the two modes across players. In a lead simulation the player on lead must be in Cards mode with all 13 cards entered.
- 3.Pick the declarer and choose contracts from the grid, any level from 1 to 7 in clubs, diamonds, hearts, spades or notrump. A run takes up to five declarer and strain pairs, and extra levels of a pair already chosen, such as 4♠ next to 3♠ by South, do not count toward the five. Set the contract as undoubled, doubled or redoubled, and the vulnerability of each side.
- 4.Choose the size of the run, 1,000, 5,000, 10,000 or 20,000 hands. A run can last up to 10 minutes.
- 5.Study the distribution charts, probability tables and double dummy results in the last step.
In a contract simulation, read the make rate first and the average tricks second. Two contracts can make about equally often while one of them takes an extra trick on many deals, which matters at matchpoints. In a lead simulation the table lists the 13 cards with the average tricks each one gives declarer, and a click on any column sorts it from best to worst. The IMP and matchpoint figures give each lead's result in scoring terms.
What the figures can and cannot tell you
Every figure is an average over the hands dealt, so it is only as good as the constraints. If North is set to 15 to 17 HCP and any shape, the batch includes hands that would have opened something other than 1NT in your system, and the result mixes them in. Tighten the shapes and suit ranges until they match the auction.
Putting several contracts in one run compares them over the same batch of deals. Larger simulations give more reliable statistics, and a small run is a cheap first look.
Double dummy play never misguesses a queen and never misses the killing lead. The figures measure what the cards allow, not what happens at the table. For one fixed pair of North-South hands and one contract, the contract success rate tool gives a single make percentage from 1,000 random layouts.
What it costs
A simulation is paid in credits, and the price depends only on the number of hands.
| Hands | Credits |
|---|---|
| 1,000 | 2 |
| 5,000 | 4 |
| 10,000 | 7 |
| 20,000 | 10 |
A new account receives 7 starter credits once, enough for three runs of 1,000 hands. Pro is $7 a month or $60 a year and includes 20 credits a month. Master is $12 a month or $99 a year and includes 55. Monthly credits do not roll over, while packs of 20, 55 and 120 credits (3.50, 8.50 and 17.50, in dollars or euros) never expire. See the pricing.
What it will not do
- It does not bid. The constraints stand in for the auction, and writing them is up to you.
- It does not model real declarer play or defense. Every result is double dummy.
- A run is capped at five declarer and strain pairs and 20,000 hands, and every run needs an account and credits.
- It is a study tool. There is no play at a table against people or robots.
Common questions
Short answers to what readers ask most.
- What is a bridge hand simulator?
- A bridge hand simulator deals many hands that fit a description and analyzes each one to produce statistics. The BridgeTricks simulator solves every hand double dummy and reports make rates, average tricks and opening lead rankings.
- What is the difference between a contract simulation and a lead simulation?
- A contract simulation measures how often contracts make across thousands of deals that match your constraints. A lead simulation fixes one contract, tries all 13 possible opening leads double dummy and ranks them by the average tricks they give declarer.
- Can I compare two contracts on the same hands?
- Yes. One run compares up to five declarer and strain pairs, at any levels, over the same deals. The results show the make rate and average tricks for each contract.
- How many hands should I simulate?
- The choices are 1,000, 5,000, 10,000 or 20,000 hands. Larger runs produce more reliable statistics but cost more credits, and a run can take up to 10 minutes.
- Is a double dummy simulation accurate?
- A double dummy simulation is exact for each deal it plays, with best play by all four hands. Real players misguess and lead the wrong suit, so treat the figures as a fair comparison of choices.
- How much does a bridge simulation cost?
- A simulation costs 2, 4, 7 or 10 credits for 1,000, 5,000, 10,000 or 20,000 hands. New accounts start with 7 credits.
Open the simulator to run your first batch. The deal generator guide covers the same constraints for dealing and exporting hands, and bridge simulation software compared sets the simulator beside other options.
Describe the hands, pick the contracts or the lead problem and run the simulation.
More tool guides
- The Bridge Deal GeneratorHow the Bridge Lab deal generator works: up to 1,000 deals that match your constraints on shape, points, honors and cards, exported as PBN or LIN.
- Contract Success RateTest how often a bridge contract makes: enter North and South, pick a contract, and BridgeTricks plays it double dummy over 1,000 random layouts.
- The Lead TrainerHow the BridgeTricks Lead Trainer grades your opening lead over 4,000 double dummy layouts that fit the auction, at IMPs and matchpoints.