Bridge Help

Bridge Rules

These are the standard NeuralPlay Bridge rules. The default game uses Rubber Bridge scoring and the SAYC bidding system. You may choose other variations and customize the rules to your liking as described in Game Settings.

Bridge is a four-player partnership game. North and South play as a team against East and West. Each hand has four stages: dealing, bidding, play, and scoring.

Dealing

At the start of the game, the dealer is chosen randomly. The deal then rotates clockwise after each hand. Bridge uses a standard 52-card deck. Each player is dealt 13 cards.

Bidding

The dealer bids first, and bidding proceeds clockwise. A player may make a bid, pass, double an opponent's contract, or redouble an opponent's double when allowed.

A bid consists of a level from 1 through 7 and a denomination: clubs, diamonds, hearts, spades, or notrump. The level is the number of tricks above 6 that the team contracts to take. For example, 3NT is a contract to take at least 9 tricks with no trump suit, and 4♥ is a contract to take at least 10 tricks with hearts as trump.

Each new bid must rank higher than the previous bid. A higher level outranks a lower level. At the same level, the denominations rank, from lowest to highest: clubs, diamonds, hearts, spades, and notrump.

The auction ends after three consecutive passes following a bid. The final bid becomes the contract. The first player on the winning team who bid the contract's denomination becomes the declarer, and the declarer's partner becomes the dummy. If all four players pass without a bid, the hand is passed out and the next hand is dealt.

Play

The player to the declarer's left makes the opening lead. The dummy then places their cards face up on the table, arranged by suit. The declarer chooses the cards played from both the declarer's hand and the dummy.

Play proceeds clockwise. Each player plays one card to a trick and must follow the suit led when able. A player who cannot follow suit may play any card. The highest trump card wins the trick. If no trump card was played, the highest card of the suit led wins. Cards rank from ace high through 2 low. The player who wins the trick leads the next one.

After all 13 tricks have been played, the declarer's team makes the contract if they took at least 6 plus the contract level in tricks. Tricks beyond the contract are overtricks. If the declarer's team takes fewer tricks than required, the contract is set, and the missing tricks are undertricks.

Rubber Bridge Scoring

When a contract is made, points for the tricks that were bid are scored below the line. Each bid trick is worth 20 points in clubs or diamonds and 30 points in hearts or spades. In notrump, the first bid trick is worth 40 points and each additional bid trick is worth 30 points.

A team wins a game by accumulating at least 100 points below the line. Part-scores carry forward until either team wins the game. A team becomes vulnerable after winning a game. The first team to win two games wins the rubber. The rubber bonus is 700 points when the opponents won no games and 500 points when they won one game.

A single contract scores game when the bid tricks are worth at least 100 points: 3NT, 4♥, 4♠, 5♣, or 5♦. A level 6 contract is a small slam requiring 12 tricks, and a level 7 contract is a grand slam requiring all 13 tricks.

Overtricks, slam bonuses, doubled or redoubled contract bonuses, undertrick penalties, and honors are scored above the line. Vulnerability increases slam bonuses and undertrick penalties. By default, honors are scored in Rubber Bridge and Chicago rubber-style play.

Complete scoring tables, including the values of bonuses and penalties, are available in many Bridge books and websites. One reference we recommend is Wikipedia.

Bidding

Bridge bidding is one of the most challenging parts of the game. If your team does not end up in the right contract after the bidding, excellent play will not help you.

There are many Bridge conventions and bidding methods. NeuralPlay Bridge supports the following bidding systems.

• SAYC (Standard American Yellow Card). A natural five-card major system with a strong 1NT opening.
• ACOL. A natural four-card major system with a weak 1NT opening.
• 2/1 Game Force. SAYC with two-over-one responses forcing to game.
• Precision. A basic strong-club system with an intermediate 1NT opening.
• Mostly Natural. Designed for beginners, this is a natural five-card major system with strong twos, a strong 1NT opening, and very few special conventions.

Conventions of the bidding system can be customized. For example, you may choose to play Roman Key Card Blackwood or play without Michaels cuebids.

Bidding explanations are provided. During the bidding or bidding review, touch a bid to view an explanation.

There are many helpful books and websites. Here are a few of the books we have found helpful.

• Standard Bidding with SAYC by Ned Downey and Ellen Pomer
• 2 Over 1 Game Force by Audrey Grant and Eric Rodwell
• Acol From Scratch by Nigel Jones
• Precision 101 by Walter Orchard

SAYC

One of the most popular methods for bidding is Standard American Yellow Card (SAYC). SAYC is a natural five-card major system with a strong 1NT opening (15–17 high-card points, or HCP). NeuralPlay Bridge supports most SAYC conventions. Supported conventions include the following.

• Stayman
• Jacoby Transfers
• Takeout Doubles
• Negative Doubles
• Fourth Suit Forcing
• Jacoby Two Notrump
• Michaels Cuebid
• Unusual Two Notrump
• Blackwood
• Gerber
• Cappelletti
• Strong Two Clubs
• Weak Twos

ACOL

ACOL is a natural four-card major system with a weak 1NT opening (12–14 HCP). Supported conventions include the following.

• Stayman
• Jacoby Transfers
• Takeout Doubles
• Negative Doubles
• Fourth Suit Forcing
• Gambling Three Notrump
• Michaels Cuebid
• Unusual Two Notrump
• Blackwood
• Gerber
• Cappelletti
• Strong Two Clubs
• Weak Twos

Mostly Natural

The Mostly Natural system may be desirable for beginners or players who want to bid naturally without many conventions. It is a five-card major system with strong two bids. Blackwood and Gerber are used to ask for aces, Stayman is used after notrump openings, and takeout doubles are used after opening bids. Many SAYC conventions are not applied.

Defensive Play

When defending, your computer partner attempts to give standard count (high-even, low-odd) and attitude (high-encouraging, low-discouraging) signals. Attitude signals are given when partner is leading or discarding. Count signals are given when declarer or dummy is leading.

At this time, the defensive signals are for your use only. The computer players do not consider signals during play. By default, the East and West computer players do not give signals.

In Settings, you may choose upside-down signals instead of standard signals. You may also turn off signals or enable signals for the East and West players.

The computer follows a standard opening-lead strategy based on the ideas outlined in this article.

Play Choices

NeuralPlay Bridge offers the following ways to play and practice.

• Chicago (rubber). Play four boards with alternating vulnerability. Part-scores carry forward until a game is made. Honors are scored by default.
• Chicago (duplicate). Play four boards with alternating vulnerability. Duplicate scoring is applied separately to each board.
• Rubber. Play hands until one team wins two games. The team with the higher total score wins the rubber. These are the default rules described above.
• Duplicate Teams. You play at table 1, and four computer players play the same board at table 2 with the directions reversed. The difference between the table scores is converted to International Match Points (IMPs).
• Daily Matchpoint. Play the day's random deals and compare your duplicate scores with those of other players. Results are scored using matchpoints.
• Daily Matchpoint (best hand). Play the day's matchpoint deals with South receiving the best hand, and compare your results with other players.
• Matchpoint Practice. Duplicate scoring is applied separately to each hand. After the selected number of hands, the team with the higher total score wins.
• Bidding Practice. Practice bidding with the computer players. After each auction, compare your contract with the contract reached when four computer players bid the same deal. The hands are not played or scored.
• Play Practice. The computer players bid all four hands, and you play the resulting contract. Duplicate scoring is used.

Learning Features

NeuralPlay Bridge offers many features to help you learn and improve your play. Most may be enabled, disabled, or adjusted in Settings. The features include the following.

• Hints. By default, the AI shows a hint when you ask for one. You may ask the AI to always show a hint, or ask it to check your bid or play and show a hint only when its choice differs from yours.
• Show HCP during bidding. Display the high-card points in your hand while the auction is in progress.
• Bidding Assistant. From the main screen menu, open the Bidding Assistant. Enter a bidding sequence and tap a bid to see its explanation.
• AI tricks taken estimate. When enabled, each play hint shows the estimated number of tricks that will be taken for each legal play. The estimate is an average across many simulations. The AI-suggested play may differ from the play with the highest estimate because of strategy or simulation noise.
• Card counter. When enabled, a counter shows which cards have been played.
• Play as direction. Choose North, East, South, or West as your seat.
• AI result. At the end of a hand, compare your result with double-dummy play or with the result when the AI plays the same contract.
• Makeable results. On the Double Dummy Analysis screen, show the makeable contracts or the number of makeable tricks for every declarer and denomination.
• Bidding practice analysis. After a Bidding Practice auction, show the par contract or compare the double-dummy result and duplicate score for your contract with the AI's contract.
• Competitive mode. Enable competitive mode to play without assistance. Hints, undo, viewing or playing all hands, HCP during bidding, and other learning aids are disabled. Daily Matchpoint uses competitive mode automatically.

Computer Players

NeuralPlay computer players offer six levels of play. Level 1 is fast and suitable for beginners. Level 3 should be fun for most players. Level 6 is the most challenging.

The computer players employ different AI methods depending on the level. Level 1 uses a rule-based AI. The AI follows rules such as: "In 3rd seat, do not trump partner's high card" and "In 4th seat, play just high enough to take the trick when an opponent is winning."

Levels 2 through 6 use Monte Carlo simulation and double-dummy analysis to determine the best play. The AI deals out the unknown cards randomly. It then tries each legal play and plays the deal to the end to get a result. This is repeated for many deals of the unknown cards. The average result for each legal play is computed, and the play with the best average result is chosen.

Levels 2 through 6 differ in how many times the unknown cards are dealt out. In general, the more deals considered, the more accurate the simulation and the better the quality of play. The trade-off is that more deals take more time, so level 6 may play more slowly than level 4 depending on the device.

Since levels 2 through 6 do not use rules for card play, you may observe surprisingly good plays or odd mistakes that do not seem to follow a logical rule. We also find that the randomness makes the computer feel more human-like and fun.

We are continuing to research and develop improvements to the computer players.

Game Settings

NeuralPlay Bridge offers many popular rule settings so you can customize the game and your practice. Rule settings include the following.

Variation

• Variation. Choose Chicago (rubber), Chicago (duplicate), Rubber, Duplicate Teams, Matchpoint Practice, Bidding Practice, or Play Practice. Daily Matchpoint games are selected directly from the main screen. See Play Choices for descriptions.

Dealing

• Fixed dealer. Allow the dealer to rotate normally, or make North, East, South, or West the dealer for every hand.
• Fixed vulnerability. Use the vulnerability determined by the selected variation, or fix it at none, North/South, East/West, or both.
• Hand characteristics. Choose random deals, a particular type of hand for one direction, a particular type of combined holding for one team, or custom characteristics for all four hands.
  • Direction. Choose the direction and deal it the best hand, a one-level opening, a balanced 15–17 or 12–14 HCP hand, a strong two opening, or a weak hand with a long suit.
  • Team. Choose North/South or East/West and deal that partnership the best hands, mostly game-or-better values, or mostly small-slam or grand-slam values.
  • Custom. Describe the HCP and distribution wanted for each direction. The format is explained under Custom Hand Characteristics.

Bidding

• Bidding system (N/S) and Bidding system (E/W). Choose SAYC, ACOL, Precision, 2/1 Game Force, Mostly Natural, or Custom independently for each partnership.
• North/South only bidding. East and West pass throughout the auction so you can practice an uncontested auction with your partner.

Custom Bidding System

These settings are used by a partnership whose bidding system is set to Custom. Major open length through Jacoby 2NT apply only to the Natural approach. The remaining convention settings apply to both approaches.

• General approach. Choose Natural or Strong 1♣.
• Major open length. With the Natural approach, require 5 or more cards or 4 or more cards to open a major suit.
• 1NT open range. With the Natural approach, use 15–17 or 12–14 HCP.
• 2/1 game forcing. Make a two-level new-suit response to a one-level opening forcing to game.
• Opening 2♦, 2♥, and 2♠ bids. With the Natural approach, play these opening bids as weak or strong.
• Jacoby 2NT. After a 1♥ or 1♠ opening, use 2NT as an artificial, game-forcing raise showing 4 or more cards of support.
• Blackwood. Choose Standard, Roman Key Card 0314, or Roman Key Card 1403.
• Gerber. Use 4♣ after a notrump bid to ask for aces.
• Michaels cuebids. Use a cuebid overcall of an opponent's suit to show a two-suited hand.
• Unusual notrump. Use an unusual 2NT overcall to show the two lower unbid suits.
• Defense over 1NT. Choose Cappelletti, Landy, DONT, or Natural.
• Jacoby transfers. Use transfer responses after natural 1NT, 2NT, and 3NT bids.
• Negative doubles. Use negative doubles through 2♠ or through 3♠.
• 1NT doubled runout. Choose redouble as a runout to a minor, a DONT-style runout, or no runout system.
• Gambling 3NT. Use a 3NT opening to show a 7-card or longer suit headed by the ace, king, and queen, with no outside ace or king.

Playing

• Count and attitude signals (N/S) and (E/W). For each partnership, choose standard signals, upside-down signals, or no signals. See Defensive Play.

Scoring

• Score honors for rubber bridge. Award honor points in Rubber Bridge and Chicago rubber-style play. Honors are enabled by default but are based largely on the cards dealt rather than the bidding or play.

Game Over

• Hands to game over. Choose the number of hands played in Chicago, Duplicate Teams, Matchpoint Practice, and Play Practice.

Deal sequences. Choose a number to determine the sequence of deals in a game. You may share the number with a friend to play the same deals. For consistent deal sequences, use random hand characteristics.

Custom Hand Characteristics

In addition to the built-in hand characteristics, you may describe the type of hand you want dealt to each direction: North, East, South, and West.

The format used to describe a hand has two parts: HCP and distribution. For example, 15-17 43xx requests 15–17 HCP, 4 clubs, 3 diamonds, any number of hearts, and any number of spades.

The HCP part specifies the number of high-card points: 12 indicates exactly 12 HCP; 12- indicates 12 or fewer HCP; 12+ indicates 12 or more HCP; and 12-14 indicates 12–14 HCP.

The second part shows the distribution in suit order: clubs, diamonds, hearts, spades. 5431 requires exactly 5 clubs, 4 diamonds, 3 hearts, and 1 spade. If an * is attached to the end of the distribution, the requirement is not suit-specific. 5431* indicates any 5-4-3-1 hand. A colon can be used to indicate "or": 4333*:5332* requires the hand to have either a 4-3-3-3 or 5-3-3-2 distribution. Commas may be used to separate ranges. 7-9,x,x,x* indicates a hand with a 7- to 9-card suit. For simple distributions such as xxxx or 2245, commas are optional: x,x,x,x is the same as xxxx. Commas are required when a range uses - or +. For example, use x,x,6+,x to specify 6 or more hearts.

The dealing algorithm is best effort. It checks many random deals against the selected criteria. When it finds a match, that deal is used. If no match is found, a random deal is used.

Examples:

After entering the custom hand characteristics, set Hand characteristics to Custom and start a new game to use them.

Hand Over

The hand-over display is shown at the end of each hand. The score display depends on the variation being played.

In addition to your result, you may show an If AI Played result or a double-dummy result.

• If AI Played. Four computer players play the same contract at another table so you can compare their result with yours.
• Double Dummy. The result with perfect play when every hand is exposed. A ✓ indicates that your card play matched an optimal double-dummy line. An * indicates that a different play could have taken more tricks. Tap the result to go directly to an optimal-play difference. The comparison evaluates your card play; the other players may have made non-optimal plays.

For Rubber Bridge, an AI result is not shown by default. You may enable one in Settings.

You may review the hand with Play Review or perform further analysis with Double Dummy Analysis, available from the menu.

Play Review

Play Review allows you to step through the play, view the double-dummy analysis of the hand, and compare your choices with optimal double-dummy play.

The Play Review menu includes the following options.

• Play from here. Replay the hand from an interesting point in the review.
• Double dummy analysis. See how many tricks can be made with perfect play and complete knowledge of the deal.

While you view the play review, a double-dummy solution using the opening lead from the hand is calculated in the background and shown when ready.

Double Dummy Analysis

Double-dummy analysis shows how many tricks can be made with perfect play and complete knowledge of the deal.

Tap a card to step through a double-dummy line of play. The green and yellow tags indicate how many tricks the team will take with perfect play if that card is played. Tap a green tag to follow a line that maximizes the number of tricks, or select another card to explore a different line.

At the start of the hand, and while the analysis remains on the line played at your table, the card played at your table is raised.

You may jump directly to your first non-optimal play or step through all non-optimal plays by choosing Optimal Play Difference from the menu. Your played card is raised, and the other tags show how many more tricks could have been taken on this particular deal. Double-dummy analysis assumes complete knowledge of this deal. A play marked non-optimal for this deal may still be the best percentage play when the hidden cards are unknown.

The HCP of each hand is shown at the bottom right. The display looks like the following.

The 6 at the top indicates that North has 6 HCP; the 7 on the right shows that East has 7 HCP; and so on.

At the top left, a table may show the makeable number of tricks for each declarer and denomination. In Settings, choose AI Analysis Features to show tricks, show contracts, or disable the table. The calculation runs in the background and may take some time depending on the deal and device. A tricks display looks similar to the following.

A makeable-contracts display looks like the following.

This table shows that 5♥ can be made when played by either North or South. East can make 2♦, but West can make only 1♦. A dash indicates that the declarer cannot make even a one-level contract in that denomination.

The par contract, "Par: 5♥", indicates that 5♥ is the contract at which neither side can improve its score by bidding further. The score for the par contract is 450 points and is always shown from the North/South perspective. If the par contract were 5♥ by East making, the score would be shown as -450 points.

In some cases, the par contract is a sacrifice. For example, East may be able to make 4♥, while North can bid 5♦ and go down only 2 when not vulnerable. In that case, the par contract is 5♦ by North, down 2. The par contract may also be passed out when no one can make a contract. In more complex cases, multiple players, possibly on different teams, can make the same bid. When this occurs, only one of the possible par contracts will be shown.

PBN Support

You may view and play deals from Portable Bridge Notation (PBN) files. Play a single deal or all deals in a file, and choose which direction to play. From the main screen, choose PBN to open a file on your device. You may also launch NeuralPlay Bridge by opening a PBN file from most email and file-management apps.

Frequently Asked Questions

How do I reset the game settings?

On the main screen, open the menu and choose Reset.

How do I change the hand sorting?

In Settings, choose Hand Sorting. You can change the rank order and suit order and choose whether to alternate red and black suits.

What are the AI results shown at the end of a hand?

You may show either a Double Dummy or If AI Played result. For If AI Played, four computer players play the same contract. For Double Dummy, the fully exposed deal is analyzed to determine how many tricks can be made with perfect play. If AI Played is not shown for Duplicate Teams because table 2 provides a similar comparison. Adjust this under AI Analysis Features in Settings.

What are shared hands?

While playing or after a hand, choose Share Hand from the menu to send it by email or another method available on your device. The auction and play are saved in PBN format. Send the hand to a friend for bidding or play advice, or send it to yourself to review later.

Can my friend without NeuralPlay Bridge view my shared hand?

Yes. Your friend can view the shared hand in a web browser. Playing the hand requires NeuralPlay Bridge on a supported device.

Does the AI cheat? How does it work?

No. Information from the auction and play is used to generate possible layouts of the unknown cards. A double-dummy solver finds the best play for each possible layout. This is repeated for many layouts, allowing the AI to estimate a good play without looking at the actual hidden cards.

Why does the computer take time to make a play?

At higher levels, the computer searches many possible layouts of the unknown cards. The time required depends on the level, deal, and device.

What does claim mean?

A claim states how many of the remaining tricks you expect to take. The app checks the claim before ending the hand. If the claim succeeds, those tricks are awarded and the hand is scored.

How do I contact NeuralPlay with suggestions and feedback?

Please email support@neuralplay.com.