Appendices

Essex Tournament ACOL

Auctions in ETA divide into three phases, which always occur in numerical order, if at all. Phases may be skipped, with the exception of phase 1. The second phase is only attempted if the player initiating it has reason to believe that game or slam is possible (indeed, the starting of phase 2 forces the bidding to at least game level). Phase three. similarly, is only attempted if the initiating bidder believes a slam is possible, although the bidding may be allowed to cease below the slam level if the logic of the auction suggests it. It might be thought that this requirement that a player must believe in game or slam possibilities before attempting phases 2 or 3 is an overly restrictive one, which in some ways it is; but we believe this is counterbalanced by the information available from the restriction (i.e. "My partner has started on phase 2, so ti must believe game is possible. So te must believe our combined points holding is over 25 points. But I've only shown 6, so ti must have at least 19. In fact ti must have exactly 19, as with more ti would have opened 2 or 2NT. But I've actually got 11 points, so the partnership holding is 30, which should be enough for a slam. I'll start phase 3.")

In the first phase, determination of the trump suit, both players bid their suits in descending order of merit until both sides in the partnership have bid the same suit naturally. This suit is thus fixed as the trump suit. After this stage, either player may, with a belief that game is possible, initiate stage 2 (cue bidding), or, with a belief that a slam is possible, initiate phase 3 (slam investigation). It is usual to go through phase 2 before phase 3 but this may not be possible. Cue bidding consists of bidding a suit, other than the trump suit, to indicate first-round control inthe suit. Cue bids are made in the most economical possible order - i.e. a player makes the cheapest cue bid available: thus skipping a possible cue bid indicates the lack of first-round control (this is a piece of 'negative inference' that BRIBIP can detect). Cue bidding stops when either player shows no more controls by rebidding trumps (at game level if possiblem or as cheaply as possible if game level has already been bypasssed).

Phase 3, slam investigation, is initiated by a bid of 4NT. This is a Roman Blackwood asking bid, enquiring about the number and nature of the Aces held by partner. The responses are forced, and are:

5

3 Aces, or none at all

5

4 Aces, or 1

5

2 Aces of the same colour (i.e. or )

5

2 Aces of the same rank (i.e. or )

5NT

2 Aces of different rank and colour (i.e. or )

If the reply to 4NT indicates that the partnership has control of all four suits, the initiating bidder may go on to ask about Kings, by rebibbinf 5NT, unless this was the reply to 4NT, in which case 6 asks about Kings, and the responses are shifted.

Should the reply to 4NT show an uncontrolled suit, the rebid is natural, unless Notrumps has been determined as the trump suit, and the natural bid wanted in 5NT. This cannot be made naturally, as it would be taken as a Blackwood request for Kings. In that case, the initiating boidder bids 5 which partner must convert to 5NT.

The criteria for deciding whether or not to bid, or to respond should partner open the bidding, is the points count. The usual requirement for a standard opening bid is 12 or more poinmts, and that for responding, 6 or more. Should responder have 12 or more (which indicates that the partnership has 24 or more) the rebid is a jump in tis best suit. Such a jump is forcing to game.

Several openging bids have conventional meanings. The table below shows the meaning of the various possible opening bids:

1

12 - 19 points, best suit Clubs

1

12 - 19 points, best suit Diamonds

1

12 - 19 points, best suit Hearts

1

12 - 19 points, best suit Spades

1NT

12-16 points, balanced hand

2

20+ points, unbalanced hand

2

weak: 4-8 points, at least 6 Hearts (7 if vulnerable)

2

weak: 4-8 points, at least 6 Spades (7 if vulnerable)

2NT

2-26 points, balanced

3

Preempt in Clubs (i.e. weak, long Clubs)

3

Preempt in Diamonds

3

Preempt in Hearts

3

Preempt in Spades

3NT

27+ points

4

Can be made in hand. Asks for a raise for every Ace held.

4

Can be made in hand. Asks for a raise for every Ace held.

4NT

5

Can be made in hand. Asks for a raise for every Ace held.

5

Can be made in hand. Asks for a raise for every Ace held.

Responses are normall natural, except in the following cases.

• Over an Opening 1NT, the system develops into a series of asking bids, such as

  2

  Stayman, asking for 4-card or better major suits

  2

  Constructive, looking for game

  2NT

  Invitational to 3NT

  etc

• Over an opening 2 which shows a strong but unbalanced hand, and says nothing abouth the strength of the Clubs, the bidding must be kept open to allow opener to bid tis best suit. Thus the bid cannot be passed. With a weak hand, one bids 2
• Over a direct game bid ( 4 4 5 or 5). one raises one level for each Ace held.

Should any player bid the same suit naturally three times, this suit is taken as the trump suit, and phase 1 finishes. Similarly, if a player reverts to tis own suit, or partner's suit, over a 3NT bid from partner, this suit is taken as trumps, and phase 1 ends. This prevents two players both insisting on their own suit.

Bridge

Bridge is played by 4 players, for a standard pack of playing cards. The players are arranged in two partnerships (conventionally called North-South and East-West) which compete against each other.

The game may be considered in two stages - a bidding stage, where the trump suit is decided, and the number of tricks required in that suit; and a playing stage, where one player on one partnership attempts to make such tricls. One player deals the cards (13 to each player) and opens the bidding should ti wish to do so. The right to bid passed clockwise round the table, until 3 playersd (or all 4 in the case of the first round) have elected not to bid.

When a player has the right to bid, ti may elect not to do so (by saying "no bid"), or may make a suitbid, or in certain circumstances may double or redouble the previous bid. A suitbid is an undertaking to make a stated number of tricks with a named suit as trumps. Since the partnership attempting to make such a contract could reasonably be expected to take the majority of the tricks, the number of tricks contracted for is in excess of 6 - i.e. the lowest level of bid is at the 1 level, a contract to make 7 (6+1) tricks. No player may attempt a contract higher than the 7 level. Any suitbid must be higher than the previous one - a bid is higher if the number of tricks contracted for is higher, or the number of tricks is equal and the suit be ranked higher. Suits are ranked (is ascending order) Clubs, Diamonds, Hearts, Spades, Notrumps (Notrumps denotes a contract where no suit is designated as the trump suit). Thus the lowest possible bid is One Club (conventionally denoted 1 ), and the highest Seven Notrumps (7NT).

Should the last suitbid have been made bay a member of the opposition, a player may 'double' the cpntract (if tis partner has not already done so). This increases the scores made should the contract be fulfilled or defeated. A member of the partnership whose bid has been doubled may 'redouble', increasing the scores still further.

After the bidding stage, or auction, the last suitbid made becomes the contract in which the hand will be played. The player in the partner ship making the bid who first mentioned the suit is known as the declarer, and will play both hands in the partnership.

The player on declarer's left leads a card, the hand opposite declarer is placed face upwards on the table, (and is henceforth known as dummy). Players must then follw to the led card, declarer choosing which cards will be played from dummy, as well as from tis own hand.

Each trick consists of 4 cards, one from each hand. A player must follow suit if possible, but may play any card should ti not hold a card of the led suit. The trick is won by the hand that contributed the highest trump, or the highest card of the led suit if no trump was contributed. Cards are ranked (in ascending order) 2 3 4 5 6 7 8 9 10 Jack Queen King Ace. The winner of each trick then leads the first card of the next trick.

Impersonal Pronouns

i.e.<.I> "Each player then looks at her hand ..."): we consider this to be worse, as the writer has clearly realised that a problem exists, but has merely changed the gender of the problem.

Throughout this thesis, we use the following set of impersonal pronouns:

Te

Him or Her

Terself

Himself or Herself

Ti

He or She

Tis

His, Her or Hers

These pronounds were first suggested by [Cullen, Giles, Lloyd & Mooney: 1976],] and are recommended for standard usage.

Some Typical Examples of BRIBIPs Bidding

January 1972, Deal 2

	Vulnerability: East/West Dealer: East
West		East
A K 8 2 Q 10 9 4 7 A 10 8 3		Q 10 3 A 8 2 10 9 4 K Q 9 2

North	East	South	West
	No	No	1
No	2	No	3
No	3	No	3
No	5	No	No
No

West does well to stay out of a slam. 3 and 3 are showing first-round control. As East skipped 3 toi cannot hold first-round control in Diamonds, and there is a certain Diamond loser. Also, West can place East with less than 12 points, from the failure to jump at round one, and so the slam does not look like a good prospect.

January 1972, Deal 3

	Vulnerability: Both Dealer: West
West		East
K 9 A 8 3 2 7 4 A K Q 9 8		A Q 8 7 3 4 A K 8 6 J 10 4

North	East	South	West
			1
No	2	No	3
No	3NT	No	4
No	4	No	4
No	4	No	4NT
No	5NT	No	7
No	No	No

This sequence can be improved on. West's bid of 4NT is superfluous, as there is already enough information to enable the reply to be predicted. 3NT is promisoing stops in all suits unbid by West, i.e. in Diamonds and Spades. Thus the first-round controls in these suits, promised by the bids of 4 and 4 must be based on Aces. We mention this to demonstrate the ease with which modifications and improvements can be added using a method-based inference system. The alteration to make the deductions above requires only the addition of two extra methods.

January 1972, Deal 7

	Vulnerability: East/West Dealer: West
West		East
K 9 8 5 2 A 7 6 5 A K Q J		Q 9 7 5 2 K Q 10 7 10 9 4 2

North	East	South	West
			1
No	1	No	2
No	3	No	4
No	4	No	4
No	No	No

January 1972, Deal 8

	Vulnerability: East/West Dealer: North
West		East
A K 10 7 4 J K J 4 A K Q 3		9 6 2 Q 9 8 Q 5 3 J 10 5 4

North	East	South	West
1	No	No	2
No	2	No	2
No	3	No	4
No	No	No

West's 2 shows an unbalanced hand with 20+points. East's 2 is the negative (less than 6 points) response. However, with game being a good possibility, East gives tentative support, which West accepts.

June 1972, Deal 6

	Vulnerability: Neither Dealer: East
West		East
A Q 10 8 A K 10 9 6 A K A 4		9 7 4 Q J 8 J 10 5 2 K 6 3

North	East	South	West
	No	No	2NT
No	3	No	3
No	4	No	4NT
No	5	No	6
No	No	No

West's Blackwood 4NT is again superfluous!

June 1972, Deal 9

	Vulnerability: Both Dealer: West
West		East
A Q 7 A J 10 9 6 J 8 4 Q 3		K 10 3 K Q 8 7 4 A 7 3 2 A

North	East	South	West
			1
No	2NT	No	3
No	4	No	No
No

July 1972, Deal 10

	Vulnerability: Neither Dealer: East
West		East
J 10 4 9 7 2 Q 7 K Q 5 4 2		A K Q 7 J 3 A 5 A J 10 8 3

North	East	South	West
	2	No	3
No	4	No	4NT
No	5	No	No
No

A curious auction. East bids Clubs 3 times, and only one of these is natural. 2 is the strong unbalnced opening bid; 4 iis natural; and 5 is the firced "I have either no or 3 aces" reply to Blackwood, which West, wisely, passes.

August 1972, Deal 6

	Vulnerability: Both Dealer: East
West		East
7 A 10 9 7 4 K 10 8 6 3 9 2		A 9 4 2 Q 6 A Q 7 A 5 4 3

North	East	South	West
	1	No	2
No	2NT	No	3
No	3NT	No	4
No	No	No

October 1972, Deal 3

	Vulnerability: Neither Dealer: West
West		East
A 7 6 3 2 Q 6 A 10 8 5 3 A		J 9 K 2 K Q J 6 K 10 8 6 5

North	East	South	West
			1
No	2NT	No	3
No	4	No	4
No	5	No	No
No

October 1972, Deal 4

	Vulnerability: East/West Dealer: East
West		East
A Q 9 5 J 10 4 2 Q 10 8 3 2		A 7 3 K 8 4 A K 8 7 K 9 5

North	East	South	West
	1	No	3
No	3NT	No	4
No	4	No	5
No	No	No

October 1972, Deal 5

	Vulnerability: East/West Dealer: East
West		East
Q 8 4 7 5 3 A K Q J 7 5 3		A 10 9 7 2 A K 10 9 8 6 A K

North	East	South	West
	2	No	4
No	4	No	No
No

West had great difficulty with tis 2nd bid (most players would). East has shown 20+ points, so a slam may be on. On the other hand, it may be disasterous, and without having had any chnace to find out about first-round conrols, West leaves the contract at the game level.

October 1972, Deal 6

	Vulnerability: Both Dealer: North
West		East
Q 10 4 2 5 3 A K Q 10 7 4 7		A K 8 7 A 10 2 9 5 3 Q 10 2

North	East	South	West
1	Dble	No	2
No	2NT	No	3
No	3NT	No	4
No	4	No	4NT
No	5	No	6
No	No	No

October 1972, Deal 7

	Vulnerability: Neither Dealer: East
West		East
K Q 9 K 9 7 3 Q 7 2 J 9 4		A J 7 A Q 10 3 A K Q 10 8 6

North	East	South	West
	2	No	2
No	3	No	3
No	4	No	5
No	No	No

October 1972, Deal 9

	Vulnerability: Both Dealer: West
West		East
Q J 9 8 6 4 A K 10 9 7 A 6		10 3 Q J 6 3 A K J 9 4 K 7

North	East	South	West
			1
No	2NT	No	3
No	4	No	4NT
No	5	No	5
No	No	No

November 1972, Deal 3

	Vulnerability: East/West Dealer: East
West		East
A 6 5 3 K 10 A K 6 A K Q 7		K J 7 2 A 9 6 2 J 10 8 6 4

North	East	South	West
	No	No	2NT
No	4	No	4NT
No	5	No	6
No	7	No	No
No

West's 4NT is not Blackwood, as the trump suit jhas not yet been fixed.

November 1972, Deal 4

	Vulnerability: Both Dealer: West
West		East
A K Q 6 3 5 2 10 8 7 6 5 2		J 10 7 A Q 8 K Q J 9 8 7 3

North	East	South	West
			No
No	1	No	1
No	2	No	2
No	3	No	3
No	4	No	5
No	6	No	No
No

In this sequence, trumps are fixed when East bids Clubs naturally 3 times.

November 1972, Deal 5

	Vulnerability: East/West Dealer: East
West		East
A K J 6 9 6 3 10 3 Q J 8 5		7 5 A 4 A K 8 6 5 4 10 6 3

North	East	South	West
No	3	No	No
No

An effective use of the preemptive opening.

November 1972, Deal 7

	Vulnerability: Both Dealer: East
West		East
A K Q 7 5 2 9 K J Q 7 4 2		10 3 A K Q J 7 A Q 4 J 8 5

North	East	South	West
	1	No	2NT
No	3	No	3
No	3NT	No	4
No	4NT	No	5NT
No	No	No

November 1972, Deal 8

	Vulnerability: North/South Dealer: East
West		East
K J 7 2 Q 9 8 3 9 6 5 3 2		10 7 6 4 A 8 A K 10 A K J 8

North	East	South	West
	2	No	3
No	4	No	4
No	5	No	6
No	No	No

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