Cryptological Techniques in Bidding and Defence

Part II

by Peter Winkler, Murray Hill, NJ, USA

In a pairs game, you open one spade and partner makes a limit raise. You hold:

AQJ63 4 AKJ8 J75

What is your call?

Your hand looks like it's going to bid four diamonds all by itself if you don't say something quickly, but of course this could be one of the many times that the opening lead will determine your score. Bids of four clubs, four no-trumps or any number of spades could be superior if you guess better than your left-hand opponent does. If you shrug your shoulders and bid four diamonds anyway, what do you do with

KJ7653 None AKJ87 J5

?

Now four diamonds gives away the club lead and doesn't solve all your bidding problems, since the ace of spades is still to be located.

Tipping off the opening lead is a well-known pit-fall of scientific bidding, and not just at matchpoints or during slam auctions. What do you do with this hand, at i.m.p.:

K KQ6 Q974 AQJ752

after you open with one club and partner raises to two (inverted) or three (limit)?

The object of crypto-conventions in non-competitive bidding is to eat one's cake and have it too, i.e. bid scientifically but without making life easy for the opening leader. Unfortunately, most crypto-conventions do not stand alone, but have to be worked into a comprehensive bidding system. Rather than speak only in generalities, the author has chosen to present some conventions which are designed for use in a five-card major system with a forcing one no-trump response, and inverted minors. The reader is encouraged to adapt them to his own system. Systems which employ many forcing bids are generally the most suitable for cryptological modifications. The conventions proposed below, for example, can be considerably expanded in Precision; in Acol it might be wiser to be content with a cryptological modification of 'trump Swiss', as in Part I of this article.

Major suit crypto-raises

The cornerstone of this system is the use of the two no-trump response to show a limit raise or better with the ace or king of trumps. The common use of 1/ – 3/ for limit raises suffers from several drawbacks:

1. it leaves no further room for game exploration;
2. the wide range in permissible trump support makes slam bidding difficult;
3. since the bid is not forcing, it cannot be given alternative meanings; and
4. the bid is valuable as a pre-empt, especially at matchpoints. What do you do when partner opens one spade and you hold

8653 754 4 Q9863

The proposed system works like this;

1/ – 3/ is pre-emptive, much like 1/ (Dble.) – 3/.

1/ – 2NT is either (a) a limit raise with the ace or king of trumps (possibly balanced with only three trumps) or (b) a forcing raise with the ace or king of trumps but only one high trump honour, and no singleton.

1/ – 3 NT is a forcing raise with at least two of the top three trump honours.

1 – 4//, or 1 – 3/4/ are splinters with exactly one high trump honour.

1/ – 1NT – 2any – 3/ or 4/ are used for all other direct raises.

Responses to 1/ – 2NT

Opener uses long-suit game-tries when he holds the trump king, short-suit with the trump ace; if he is intenested in a slam opposite a good limit raise, he can cue-bid at the four-level either now or later; opener's first cue-bid is normal if he has the trump king (or queen in a 1/ -3NT sequence) but negative if he holds the trump ace. If opener holds neither of the top two trumps he is limited to three or four of the major or no-trumps and five-level asking bids.

Here are some sample sequences.

AQ642 8 K976 A42

1 3 No

2NT 4

KJ8 964 AQ532 83

KQ642 8 K976 A42

1 3 No

2NT 4

A98 964 AQ532 83

AQ642 8 K976 A42

1 3 No

2NT 3NT

K983 KQ103 1052 QJ8

KQ642 8 K976 A42

1 3 3

2NT 3 No

A98 KQ64 Q52 843

On slam sequences responder avoids raising opener's cue-bid, whether positive or negative, so as to prevent the opponents from making either informative doubles or inferences from their absence. Instead he communicates by level.

AQ7642 K983 7 A4

1 3 4 6

2NT 3 5 No

K983 A6 J542 K85

KQ7642 KQ83 74 A

1 4 5 No

2NT 4 5

A983 A6 J532 K85

K10642 83 KQ74 AQ

1 4 4

3NT 4 No

AQ98 64 A53 K853

Q76432 None AKJ7 Q42

1 4 5 6

3NT 4 5NT No

AK98 Q643 QJ53 K8

976432 8 AKQ74 A	1 4NT 7	3NT 5(a) No	AK85 A643 53 Q85
(a) Three aces, or two aces and the king of trumps.

Q10643 8 A7 AK764

1 2 No

1NT 4

J9852 AK6 K5 J85

Many more examples could be given but the principle is clear; location of the trump honours makes slam bidding easier, and the opening leader will sometimes misguess the correct interpretation of the auction.

Minor suit crypto-raises

The minor-suit raise structure uses both 1/ – 2/ and 1/ – 2 NT to show a limit raise or better, forcing to three of the minor; the former shows the ace or king of trumps, the latter both or neither. Only 1/ – 2/ leads to encrypted auctions; opener bids a stopper when he holds. the trump king, a non-stopper when he holds the trump ace. Here location of the top trump honour helps opener decide whether his suit will run in three no-trumps.

A64 8 K97643 A107

1 2 3NT

2 2NT No

J8 AJ64 A852 J85

A64 8 K97643 A107

1 3

2NT No

J8 AJ64 QJ52 Q85

KJ64 83 AQ764 A7

1 2 3 5

2 2 4 No

A8 642 K852 KQ85

74 AJ83 KQ764 A6

1 2 3 5

2 3 4 No

J85 K6 A852 KQ83

Other sequences

Obviously, key-card raises can be set up for rebids by the opener and in other situations. Some conventions require very little modification to 'encrypt': an example is disciplined weak two-bids, where a weak two-bid in first or second position guarantees two of the top three trump honours. It seems natural to let the two no-trump response show the remaining honour, whereupon opener bids his feature with the side suits rotated in accordance with his trump holding. Thus, for example, 2 – 2NT – 3 might show either the ace-king of spades and a club feature, the ace-queen of spades and a diamond feature or the king-queen of spades and heart feature. Responder's rebid, if not game or three spades, is a specific asking bid whose identity is rotated by the same scheme.

If key-card raises do not fit nicely into your system, you can still encrypt cue-bids by using possession of the trump ace as the key. The first cue-bid by the (eventual) declarer after a suit has been agreed upon shows either the ace of the suit or the trump ace but not both; succeeding cue-bids are normal. Here special bids are needed for confirming the key; for example: after an encrypted four club bid, four no-trumps shows either the trump ace and the ace of the higher-ranking side suit, or the club ace with the ace of the lower-ranking side suit. A raise to five clubs instead shows the reverse.

The ultimate weapon of the bridge cryptologist is "system encryption." For this the partnership needs two entirely different convention cards, and a collection of methods for establishing a key early in the auction in order to determine which card to use. As an example of an early key establishment, suppose a response of one heart to a forcing one club opening shows one of the minor-suit aces, while one spade shows one of the major-suit aces. Any rebid by opener other than one no-trump confirms possession of the missing ace, and that and subsequent bidding are in accordance with (say) the first convention card if responder's ace is higher ranking and the second otherwise. At present such extreme measures cannot be taken seriously, but who knows what the future will hold?

In any case the next instalment of this series will show that the objectives of encrypted bidding are not limited to concealing from the opponents the killing opening lead.

Editor's note:

• Thanks to Marcel den Broeder of the Netherlands, who located the text of these four linked articles in a Dutch library.
• First published in the English "Bridge Magazine", in May 1981.

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