Scoring

Rubber Bridge

In this form of bridge two pairs play against each other. As the name suggests, the basic unit of play is a rubber, which is the best of three games. In rubber bridge, a game is won by the first pair to score a total of 100 or more points for successful contracts, over several deals if necessary.

A pair who has already won one game toward the current rubber is said to be vulnerable. A pair who has not yet won a game is not vulnerable. A vulnerable pair is awarded higher bonuses but is also subject to higher penalties than one that is not.

The score is kept on a piece of paper divided into two columns, one for each pair, with a horizontal line part-way down. Scores for successful contracts are entered below the line, and count toward winning a game. Other scores, such as bonuses for tricks made in excess of the contract (overtricks), or penalties for tricks short of the contract (undertricks) are entered above the line, and do not count toward winning the game.

For a successful contract, a score equal to the contract value is entered below the line in the declaring side's column. The value of the contract is computed on the basis of the number of tricks stated in the contract (which may be smaller than the number of tricks actually made). If the contract has not been doubled, each trick is evaluated as follows:

For example, a 1NT contract is worth 40 points, a 3♠ contract is worth 90 points (30×3), and a 2NT contract is worth 70 points (40+30).

If the contract was doubled the contract value is also doubled; if it was redoubled, the contract value is multiplied by 4. Additionally, the declaring side scores an extra 50 points above the line for making a doubled contract, and 100 points above the line for making a redoubled contract. The declaring side also gets an extra bonus above the line for contracts at the six (small slam) and seven (grand slam) levels. This bonus ranges from 500 points for a non-vulnerable small slam to 1500 points for a vulnerable grand slam.

If the declaring side wins overtricks, it earns a score above the line for the overtricks in addition to the score below the line for the contract. If the contract has not been doubled, overtricks are scored at the same rate used to compute the contract value: 20 points per overtrick for minor suit contracts, or 30 points per overtrick in major suit or no trump contracts. If the contract was doubled or redoubled, the bonus for overtricks does not depend on the contract denomination, but instead depends on whether the declaring side was vulnerable or not, as shown in the table below.

If the contract is set, neither side scores anything below the line, but the defending side earns a score above the line. This score depends on the number of tricks the contract was defeated by (undertricks), on whether the declaring side was vulnerable or not, and on whether the contract had been doubled or redoubled. In the case of an undoubled contract, the defending side collects 50 points per undertrick if the declaring side was not vulnerable, and 100 points per undertrick if the declaring side was vulnerable. The score awarded to the defending side increases significantly (by a factor of two or more) for doubled or redoubled contracts.

Points above the line can also be earned by holding certain honors combinations in one's hand (honors are the top five cards in a suit: A K Q J 10). In a suit contract, if one player holds four (resp. five) honors in the trump suit, that player’s side is awarded a bonus of 100 (resp. 150) points above the line. In a no trump contract, if a player holds four aces, that player’s side scores 150 for honors. As there is no skill involved in being dealt a particular set of cards, players often agree to play without the honor bonuses.

A side that accumulates 100 points or more below the line wins a game. A new line is then drawn under the scores. Anything the opponents had below the line does not count toward the next game; they start from zero again. The side that first wins two games wins the rubber, and they get a bonus of 700 points if they won it two games to zero, or 500 points if it was two games to one. An example of a rubber score is at the bottom of this page.

Usually multiple rubbers are played. At the end of the play, both sides’ scores are totaled, and the pair with the higher score wins.

Duplicate Bridge

Unlike at rubber bridge, at duplicate bridge every deal is scored separately and no part scores are carried forward. The scoring of each deal is always zero-sum, that is, North-South's score is always the opposite of East-West's. The declaring side always get a positive score if they make their contract, while the defending side always gets a positive score if the contract is set. What follows is a basic outline of duplicate bridge scoring, with many details omitted.

If the contract is made, the declaring side's score is the sum of three components:

• The value of the contract
• The value of overtricks, if any
• An additional bonus

The value of the contract is computed on the basis of the number of tricks stated in the contract, as in rubber bridge. Trick evaluation, too, follows the same rules used in rubber bridge. For example, if the contract has not been doubled the value of each trick is as follows:

The same scale applies to the value of overtricks: 30 points per overtrick in notrump and major suit contracts, and 20 points per overtrick in minor suit contracts (again, assuming that the contract has not been doubled).

The additional bonus depends on the value of the contract. Contracts worth less than 100 points (part-score contracts) are awarded a 50-point bonus. Contracts worth 100 points or more (game contracts) receive a bonus of 300 points if the declaring side is not vulnerable, and of 500 points if the declaring side is vulnerable. There are also special bonuses for contracts at the level of six (small slam) and seven (grand slam). They range from 500 points for a non-vulnerable small slam to 1500 points for a vulnerable grand slam, and they are awarded on top of the game bonus. Honor bonuses are never awarded at duplicate bridge.

If a contract is set, the score awarded to the defending side depends on the number of tricks the contract was defeated by (undertricks), on whether the declaring side was vulnerable or not, and on whether the contract had been doubled or redoubled. In the case of an undoubled contract, the defending side collects 50 points per undertrick if the declaring side was not vulnerable, and 100 points per undertrick if the declaring side was vulnerable. The points awarded to the defending side increase significantly (by a factor of two or more) for doubled or redoubled contracts.

Here are a few examples illustrating the scoring rules:

• If the contract is 2♥ (not doubled) and the declaring side wins 10 tricks (makes 4, in bridge jargon), the declaring side is awarded 170 points (60 for the contract, plus 60 for two overtricks, plus a 50-point bonus).
• If the contract is 3NT (not doubled) and the declaring side wins 9 tricks, the declaring side is awarded 400 points if they are not vulnerable, or 600 if they are (100 for the contract, plus a 300/500-point bonus).
• If the contract is 4♣ (not doubled) and the declaring side wins only 8 tricks (down two), the defending side is awarded 100 points if the declaring side is not vulnerable, or 200 if the declaring side is vulnerable (50/100 points per undertrick).

As mentioned earlier, this is only an outline of how duplicate bridge scores are computed. A more detailed explanation is given here, and a complete chart of all possible scores is here.