What Is Duplicate Bridge? How It Works and How It Is Scored

Duplicate bridge is the form of bridge in which the same deals are played at every table, and your result on each deal is compared with everyone else who held the same cards. That takes the luck of the deal out of the score: good cards do not help you, because the pair at the next table had them too. Clubs, tournaments and ACBL online games all use it.

Duplicate bridge at a glance:

• The same deals are played at every table, carried from table to table in boards.
• Your result on each deal is compared with the other pairs who held the same cards.
• Pairs events are scored in matchpoints, team events in IMPs.
• Masterpoints are awarded for good placings in ACBL-sanctioned games.

The name comes from the fact that every deal is played again, or duplicated, at the other tables. The idea is older than bridge itself. Whist players were comparing results on the same deals in the 1850s, and John T. Mitchell, who gave his name to the most common movement, wrote a book called Duplicate Whist. Duplicate bridge is also called tournament bridge.

Duplicate, rubber and Chicago bridge: the difference#

The auction, the play and the trick-taking rules do not change. Only the scoring and the way the cards are handled are different, so everything you learned at a home table carries straight over. Chicago takes its name from the Standard Club of Chicago, where it began in the early 1960s, and because its game bonuses match duplicate, the ACBL describes duplicate as scored like Chicago or party bridge.

Boards and movements#

Each deal lives in a board: a tray with four pockets marked North, South, East and West, plus the dealer and the vulnerability. Players take their 13 cards from the pocket, bid and play, and after each trick keep their own cards in front of them rather than throwing them into the middle. At the end of the hand, the cards go back into the pockets unchanged, and the board moves on to the next table.

A movement decides who plays which boards against whom. In the common Mitchell movement, North-South pairs stay put while East-West pairs and the boards move in opposite directions, so no pair ever plays the same board twice. In a Howell movement the pairs follow a printed schedule, switching between North-South and East-West, so that each pair meets all or most of the other pairs; clubs usually use it when there are fewer than about seven tables. Because a Mitchell only compares you with pairs who sat your direction, it has two winners, one North-South and one East-West. A Howell mixes everyone together and has a single winner. Each board carries a traveler, a score slip that records every result so the pairs can be compared at the end. Online, the software handles all of this and you simply see the next board.

Dealer and vulnerability by board number#

The board number fixes who deals and who is vulnerable, under Law 2 of the Laws of Duplicate Bridge. The same pattern repeats for boards 17 to 32 and every later group of 16.

Duplicate bridge scoring: the score for one deal#

Every deal is scored on its own, and nothing carries over to the next one. If you make your contract you score the trick points plus a bonus. If you fail, the other side scores for each trick you were short.

Suppose you bid 4 spades and take ten tricks, not vulnerable. Four tricks at 30 make 120 trick points, which is a game, so you add 300 and score plus 420. Vulnerable, the same result is worth plus 620. Overtricks score at the trick value, so eleven tricks would be plus 450. If you are new to trick values, How to Play Bridge covers them in its scoring step.

Three things work differently from a home game, and Bridge Rules for Beginners sets them side by side. Nothing carries over: each board stands alone, so a part score on one board does not help you toward game on the next. Honors are not scored at all. And if all four players pass, the board is not redealt. Both sides score zero and the board moves on, because the other tables must play the same cards.

Doubled and redoubled contracts#

A double multiplies the trick score by two and a redouble by four, and the penalties grow even faster. These are the values from Law 77:

Say the opponents double you in 3 hearts, not vulnerable. If you make it, the trick score is 90 doubled to 180, which is a game, so you score 180 plus 300 plus 50 for the double: plus 530. If you go down two, the opponents score 100 plus 200: plus 300 to them.

Matchpoint scoring for pairs#

In a pairs game, your raw score on a board (say plus 420 for making 4 spades) is compared with every other North-South score on that board. You receive one matchpoint for each pair you beat and half a matchpoint for each pair you tie. The matchpoints are added across all boards and expressed as a percentage. Fifty percent is average. This changes the strategy: overtricks and small extra scores can matter as much as making the contract, because beating the other tables by 30 points is worth as much as beating them by 500.

Here is one board played at five tables, North-South not vulnerable:

The pair with plus 450 beat all four other pairs and score 4 out of 4, a top. The two pairs with plus 420 beat two pairs and tie with each other, so each gets 2.5. One overtrick turned a good board into a top.

How matchpoints change your choices#

Because only the number of pairs you beat counts, the higher-scoring contract wins even when both make. With an eight-card major fit, not vulnerable, 4 hearts making ten tricks is plus 420, which beats 3 notrump making nine at plus 400. In a minor the sum works the other way: 5 clubs making eleven tricks is plus 400, which loses to 3 notrump making ten at plus 430. That is why duplicate players work hard to reach 3 notrump instead of a minor-suit game.

Part scores follow the same logic. Two spades making eight tricks (plus 110) beats 1 notrump making seven (plus 90), so both sides fight for the part score instead of letting the opponents play at the one level. An overtrick, or one undertrick saved, counts for far more than it does at a home table.

From matchpoints to a percentage#

The most you can score on a board, called a top, is one less than the number of pairs sitting in your direction. With eight pairs in each direction the top is 7. Over 24 boards the maximum is 168, so 92.4 matchpoints is 55 percent. The percentage is what makes a small club game comparable with a large one.

IMP scoring for teams#

In a team game, two teams of four sit at two tables. Your North-South pair plays a set of boards against their East-West pair, while your East-West pair plays the same boards against their North-South pair. Your team's two scores on each board are added together. Usually one is a plus and the other a minus, but you can be plus at both tables, for example by making your game at one table and beating the opponents' contract at the other. The net figure is converted into International Match Points using a fixed scale. A difference of 20 points is 1 IMP, a difference of 450 points is 10 IMPs, and the scale tops out at 24 IMPs. Under IMPs, making your contract matters far more than overtricks, so the bidding is bolder and the play safer.

An example: vulnerable, your North-South pair bids 4 spades and makes ten tricks, plus 620. At the other table their North-South pair stops in 3 spades and also takes ten tricks, plus 170, so your East-West pair scores minus 170. Your team is 450 points ahead on the board, which the scale below turns into 10 IMPs. Had both tables bid the game, the board would have been a push at 0 IMPs.

Pairs and teams are the two main formats. Some clubs also run individual games, where you change partner every round, and team events are sometimes scored board-a-match, where each board is simply won, lost or tied.

Matchpoints or IMPs: how the scoring changes your play#

The cards and the rules are the same in both forms of scoring, but the right decision often is not. At matchpoints you are trying to beat as many pairs as possible, by any margin. At IMPs you are trying to win big swings and avoid losing them.

Two examples show the difference. Vulnerable at IMPs, bidding a game that is no better than a coin flip still pays. If 4 spades makes, you score plus 620 instead of plus 170 in 3 spades, a gain of 450 points or 10 IMPs. If it fails by a trick, you score minus 100 instead of plus 140, a loss of 240 points or 6 IMPs. Winning 10 when you are right and losing 6 when you are wrong means the game is worth bidding if it makes a little under 40 percent of the time. Not vulnerable, the numbers are 6 IMPs won against 5 lost, so you need about 45 percent.

At matchpoints, a sacrifice can turn a bad board into a top. Suppose the opponents are vulnerable and can make 4 hearts for plus 620. If you bid 4 spades, not vulnerable, and go down three doubled, you lose 500. Every pair that let them play 4 hearts lost 620, so your minus 500 beats them all. At IMPs the same save gains only 120 points, which is 3 IMPs.

How to score duplicate bridge by hand#

Clubs use software, but scoring a small home duplicate on paper takes only a pencil and a traveler for each board:

1. After each board, North writes the contract, the declarer, the tricks taken and the score on the traveler, and East-West check it.
2. Score every result with the tables above. Write a plus score in the North-South column or the East-West column, never both.
3. When the session ends, list the North-South scores on each board from best to worst.
4. Give each pair one matchpoint for every score it beat and half a matchpoint for every tie. The East-West pair at the same table gets the top minus the North-South matchpoints.
5. Add each pair's matchpoints across all boards and divide by the maximum possible to get the percentage.

Masterpoints#

In North America, the American Contract Bridge League awards Masterpoints for good finishes in sanctioned games. They accumulate for life and mark your progress through ranks such as Junior Master, Life Master and beyond. Online robot games sanctioned by the ACBL award Masterpoints too, as the next section explains.

Duplicate bridge online#

Online, the boards, the movement and the scoring are all handled for you. The robots fill the other three seats, and your result on each board is compared with everyone who played the same cards.

On Online Bridge Club, Game Day is an 18 or 12 board ACBL-sanctioned game that you play over the course of a day. It earns Masterpoints, badges and free credits, and each day's games end at 4:00 AM Eastern Time. Insta-Game is a 12 board game with instant feedback: after each board you see your score and what was possible. Each Insta-Game costs 2.25 SB Credits and earns Masterpoints too. Bridge clubs can also run their own games on Online Bridge Club.

Shark scores both games at matchpoints only, and both award ACBL Masterpoints, so the IMP sections above apply to club and tournament team games rather than to Online Bridge Club.

For practice outside a sanctioned game, Shark Bridge Game seats you with three robots. After a hand is scored, the review button shows how the robots bid and played the same cards at the "closed" table, side by side with your auction and your play. That is the same comparison a team match makes, one board at a time, and How to check how robots played the hand shows where to find it.

Duplicate etiquette that differs from kitchen bridge#

• Cards are not gathered into the trick. Each player keeps their own cards, turned to point at the winning side.
• Most clubs and tournaments use bidding boxes instead of spoken bids. Online you click a button.
• Unusual agreements are alerted, and in ACBL games a few common ones, such as your notrump range and transfers, are announced instead. The opponents may ask about any call at their turn.
• The director settles every irregularity. Calling the director is routine.
• Keep any talk about a board short and quiet, and never where another table can hear, because they may still have to play it.

The Rule of 7 and the Rule of 9#

Both rules are often mentioned alongside duplicate bridge, but neither is a duplicate rule. They are guidelines that help in any form of the game.

The Rule of 7 helps the declarer in a notrump contract decide how long to hold up an ace. When the defenders lead a suit in which you have only one stopper, add the cards you and dummy hold in that suit and subtract the total from 7. The answer is how many times to duck before you win. With three cards in your hand and two in dummy, 7 minus 5 is 2, so you duck twice and win the third round.

The Rule of 9 helps you decide whether to pass partner's takeout double for penalties. Add the level of the opponents' contract, the number of cards you hold in their suit and the number of honors (ace, king, queen, jack or ten) you hold in it. With 9 or more, pass and defend. It is a rough test, not a law, and How to Evaluate a Bridge Hand covers the counting methods you will use every day.

Duplicate in a lesson#

Teachers like duplicate because it lets a whole class play the same deal and then compare. In Teacher's Console a teacher can run a short duplicate game inside a lesson and go over the hands with the class between rounds; the manual Lesson in a Duplicate Game and Duplicate Game in a Lesson shows the setup step by step.

Your first club game: what to expect#

Duplicate is still bridge, so you do not need to study anything new before your first game. A few habits will make the evening easier.

• Look for a newcomer game. The ACBL describes these as games for players new to duplicate, not necessarily new to bridge. Many other games are stratified, so you are compared only with players at your level.
• Bring a partner if you can. If you cannot, call the club ahead and ask the manager or director to find you one.
• Fill in a convention card with your partner before the game. It tells the opponents what your bids mean, and a simple standard card needs only a few boxes. Shark's robot convention card is a filled-in example.
• Ask for an East-West entry. North keeps the official score for the table, so East-West can concentrate on the cards.
• Expect about seven and a half minutes per board. A round of two boards takes about 15 minutes and a round of three about 20, then the director calls the move.
• Make your opening lead face down. Your partner can still ask about the auction, and if it was not your lead nothing has been exposed.
• Keep your private score on the back of your convention card and keep the card folded, because it shows results on boards other tables have not played yet.
• If anything goes wrong, such as a revoke, a lead out of turn or a board with twelve cards, call the director. Nobody minds, and players should never sort out an irregularity themselves.

If you would like a structured route to that first evening, follow a four-week plan that ends with your first game.

Start with a robot game#

Play a few robot games first. Shark Bridge Game gives you a table with three robots and no director watching, as Play Bridge 4 Hands describes, and the ACBL robot games on Online Bridge Club are a low-pressure way to earn your first Masterpoints. You can also join a Play & Learn game, where a teacher reviews the hands after each round. If you want lessons first, the Recommended Teachers directory lists instructors who teach online and in person, and how to choose a bridge teacher explains the formats. If you are still learning the game itself, Bridge Rules for Beginners covers the table procedures, Bridge Bidding Basics covers the auction, and Bridge Conventions Explained covers the bids you will hear alerted.