Duplicate Bridge is similar to Contract Bridge

Duplicate bridge is an extended form of contract bridge in which identical deals are played at multiple tables to compare the scores and decide the winner.
The advent of contract bridge was soon followed by many clubs and tournaments switching to duplicate versions of the game to make the competitions relatively sharper, as also fairer. The element of skill (and almost zero dependence on chance) inherent in various forms of duplicate bridge has made it extremely popular among the contract bridge players all over the world.

Basic Format of Duplicate Bridge

Duplicate bridge can be played by a minimum of eight players sitting at two tables, or could extend to as many players/tables as the organizers may permit. The basic premise behind duplicate play is that the hands dealt to the players sitting in a particular direction (North, South, East and West) on all the tables are identical.
A board (a word typically used in duplicate bridge to specify a deal) is passed from one table to another at the end of game-play. In the online scenario, the boards are simply duplicated in tandem without the hands being available for viewing by players of the other competing tables.

Types of Duplicate Bridge Events

The three duplicate bridge events commonly played in clubs and tournaments are:

Individual Events

Duplicate Bridge is similar to Contract BridgeIn this form of duplicate play, the partnership does not remain constant throughout the game/event. In other words, a player is assigned a different partner after every round of play. (A round may comprise of a single board or more – though not more than three in majority of the settings).

The individual event is perhaps one in which the chance factor could influence the results to fairly great extent, because a player is never sure of the compatibility he can have with his next partner. The individual format, as such, finds relatively less favor with most of the duplicate bridge players.

Pair Events

As the name suggests, two players form a team to play as partners for the entire duration of the event. This fixed partnership factor obviously brings in enhanced stability to the game since the partners can bid and play with a sound understanding.
Pair game is considered as the most popular of the duplicate bridge events. There are quite a few variations of the pair events depending on a host of diverse criteria.

Team Events

A team event is akin to the pair game except that the team has four players (two partnerships) playing at two tables. One pair of the team sits as North-South at the first table with the second partnership automatically assigned the East-West seats at the other table.

A team, in fact, can comprise of four to six players with four of them playing in any one session (or, when a substitution is permitted by the director of a tournament). There are a number of variations of the team game too, the most common ones being Swiss, knockout and board-a-match.

Duplicate Bridge Movements

As per the rules of duplicate bridge, any one pair, having played a particular board just can not get to play the same hand once again. Each of the boards is also required to be played at all the tables. These prerequisites coupled with other organizational and fair-play requirements, the boards (and the players in some cases) are made to move from one table to another after a round, following a plan laid down by the authorities.

Any of a number of movements can be selected for a tournament depending on its type/size. The most popular of the lot is Mitchell movement, which is a generally preferred for use in most clubs and tournaments. The Howell movement, though a little more complicated, is also extensively used (especially, when the number of tables is relatively fewer).

Scoring in Duplicate Bridge

The scoring in duplicate bridge is entirely different vis-à-vis rubber bridge. In rubber bridge, the partnerships always aims at scoring more points than the opponent after being dealt with different hands in every successive rounds. The scoring in duplicate play, on the other hand, is based on a comparison of the performance of the teams when playing individual boards with identical sets of cards.

Depending on the organizers and the type of event being played, the method of scoring in duplicate bridge differs. Nevertheless, the two methods normally employed are:

Matchpoint Scoring. A very commonly used method, particularly considered suitable for pair events. These points are awarded to the teams in terms of percentage scores – the maximum being 100% and the minimum, 0%.

IMP Scoring. IMP is an abbreviated form of International Match Points. After comparing all individual scores, the differences are converted to IMP using a standard table. This method can be used effectively for all the three (individual, team and pair) events.

Apart from being totally different from rubber bridge scoring, these two duplicate bridge scoring methods are distinctly dissimilar from each other too. It thus becomes vital for the partnerships/teams to work out appropriate strategies before playing in tournaments using either of the methods.