I fully understand and agree with the rule "do not communicate in illegal ways" (pose, tone of voice, etc), but I don't quite understand the point in requiring the disclosure of one's bidding system to one's opponents. What does this aim to achieve?

True disclosure sounds hard to achieve in practice. Partners know each other's habits, and as a result bidding communication still has "hidden" parts - it is just not possible to describe every habit to opponents.

This raises a related question. Suppose the bidding system should be disclosed. Why not then require only a single bidding system for all players?

  • re "Why not a single bidding system for all players?" It exists; it's called SAYC, or Standard American Yellow Card, and it is unplayable by any competent player of even Auction Bridge because of its simplicity and irrationality. I say the latter since if combines too agreements that exist nowhere except SAYC because they are mutually incompatible: 5-card major openings and a natural 1NT response to an opening bid of 1 of a major suit. Consequently only extreme novices play SAYC.. Commented Mar 17, 2016 at 1:33

5 Answers 5


Bridge players hate guessing.

Allowing non-disclosure will basically turn the game into a pointless guessing game, with luck (and to some extent, the bidding system) becoming the predominant factor, rather than skill. This will surely drive away the good players, and all that will be left will be self proclaimed bidding theorists...

Just because you cannot achieve 100% full disclosure does not mean you get rid of it completely.

The current rules [of full disclosure, different systems] allows for (somewhat reasonable) innovation in bidding while trying to pit opponents on an even ground, making skill the predominant factor. Making skill the main factor, with the right amounts of luck, is what keeps people coming back.

  • I don't think eliminating mandatory disclosure would take out skill at all. Deciphering the opponent's bidding system would be a really interesting skill to include in the game. Plus, even if you haven't fully diciphered theirs, there is still plenty of skill in playing without that knowledge. Commented Apr 20, 2018 at 2:23
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    @evanrmurphy: So you play a total of 2 hands against a pair in a Matchpoint tournament. What do you think you will manage to decipher?
    – Aryabhata
    Commented Apr 20, 2018 at 4:42
  • It's a good point. The dynamics would change quite a bit. One interesting feature of the change is that players who dominate tournaments for some time would have their bidding systems studied and deciphered more than other players. Commented Apr 20, 2018 at 19:12
  • So new players would have some advantage from their bidding system being still undiscovered, while established players would be defending a known bidding system. Commented Apr 20, 2018 at 19:49
  • @evanmurphy: Players who dominate tournaments would be well advised to keep changing their system. Not having full disclosure is completely impractical IMO and seems like you are ultimately trying to achieve full disclosure anyway!
    – Aryabhata
    Commented Apr 20, 2018 at 23:34

If the bidding system is not disclosed, then it becomes trivially easy to cheat. With knowledge of your bidding system however, I can now determine that your bidding was indeed consistent with how you got to your final contract. (My system notes with one partner comprise over 30 pages of densely typed notes, and some expert partnerships have much more than that. It is not necessary to have such complete notes, but it can be useful, especially if some question comes up about one of our bids. On long drives to a tournament, my partner and I usually spend the time discussing these notes, often adding new points as we think of them. It all depends on your investment in the game.)

As an example, long ago, in a galaxy far, far away, I played a lot of pinochle. Partner and I developed a complete bidding system for pinochle, that was completely disclosed to our opponents. The only information passed was by the numeric jump of our bids, but we did reasonably well in passing what info we needed. Our frequent opponents were told of our system, and we explained the bids as we made them. Interestingly, after a while, our results suddenly went downhill, then we found out why. Our opponents had come up with their own secret system, that involved tugs on their ear, etc. We gave up the game completely, as there was no longer any reason to play, certainly against those opponents.

The point is, without disclosure, the game is a waste of time, no longer a game at all. At the very least, it is no longer bridge.

Next, bidding is indeed a major factor in bridge. If you think that just knowing what contract you are in is all you need to know in bridge, then you have a lot to learn. A huge part of bridge is correlating ALL of the available information at hand, bringing it all together and using that information to then play the hand. For example, did your opponents overcall? Did they bid at all? Even if they did not, it is still a case of the dog that did NOT bark in the night. Use all information to play the hand. Until you do that, you are still a novice.

  • Pinochle needs a new bidding system, because the currently accepted bidding system is full of holes and flaws. If your invented system was good, please share it at powerpinochle.com/forum/ Several of our members would love to use a better system. Commented Feb 21, 2017 at 13:54
  • "Our opponents had come up with their own secret system, that involved tugs on their ear, etc." But these kinds of signals are external to the bidding system. These wouldn't be allowed in bridge even if you did disclose them! As long as players are only using in-game signals like bidding, non-disclosure wouldn't necessarily hurt the gameplay, and it might even make things more interesting. Commented Apr 20, 2018 at 2:34

Imagine the opportunities for abuse. Without a disclosure rule, partners can make up any system they want and thereby communicate in illegal ways. There's really no difference to the other players between "qble and Monica's private bidding system that we won't disclose" and conducting the conversation in Swahili; either way it's obfuscating information that should be available to all players.

(I am neither a bridge player (my husband is) nor a speaker of Swahili, just in case that matters.)

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    A counterargument would be as long as the communication is done in the language of legal bidding and nothing else, why should meaning be disclosed? If you can obfuscate the communication that way, and still end up in the right contracts, congrats to you. Commented May 21, 2013 at 16:05
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    I agree with Aaron's conterargument. Bidding is literarly too thin channel for info passing, especially taking into account interfering with ops and penalties for wrong contracts. Moreover some tournaments rules asks not only to disclose convention itself but also to develop and disclose defending strategy against it - that is too artifical.
    – qble
    Commented May 21, 2013 at 20:22
  • @qble: re "Bidding is literarly too thin channel for info passing"; Clearly you have never watched or played the game at a high level. The channel is remarkably high-bandwidth as played by expert players. The key to widening the bandwidth is understanding the meaning of all the calls and bids not made. Commented May 22, 2013 at 0:11
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    +1, Very astute for a non-player; I assume your husband is more than merely competent. Commented May 22, 2013 at 0:12
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    @AaronMorris the point is that if your bidding is non-disclosed, then how can it be determined if you are communicating illegally? With full disclosure, I can come back and be able to agree that you did indeed communicate legally, as long as your bids are consistent with your agreements.
    – user3264
    Commented Jun 19, 2013 at 21:14

It is a "sporting" rule as much as anything else.

The opponents need to be given an opportunity to learn your bidding system. Some will take it, and some won't. But you can't have a situation where the opponents had "no chance" at understanding.

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    Opponents always can understand, at least something - from game mechanics. Placing wrong bid at high level would lead to penalties, if such penalties are not enough then maybe mechanics should be adjusted? Or just imagine chess, where after each move you would had to explain all your intent to op, otherwise "he would not have chance at understanding" + you would have to provide all openings you use and know before game, so he would have "opportunity to learn your openings".
    – qble
    Commented May 22, 2013 at 1:10
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    @qble: In chess, you can SEE everything. Whether you "understand" it or not is up to you. In bridge, opponents are supposed to be able to "hear" everything, and not in Swahili either, as Monica pointed out. But of course, you hope that they don't fully understand.
    – Tom Au
    Commented May 22, 2013 at 1:13
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    Unknown bid system is not Swahili - partners who use it are acting within game mechanics, with possible fines for "wrong" actions, etc. Ok, another example - football forward before match should send his habbits description during penalty beating to goalkeeper. Otherwise goalkeeper would jump in wrong direction...
    – qble
    Commented May 22, 2013 at 1:22
  • @qble It sounds like there's an additional excellent question there: what exactly does it mean to disclose a bidding system, and what determines whether it's a legal one?
    – Cascabel
    Commented May 22, 2013 at 1:26
  • @Jefromi I guess this is addressed by special formalistic forms like "ACBL Convention Card". By the way, at some tournament rules some types of bidding systems are banned (like non-natural, too artifical), which beats following @Pieter's evolution argument
    – qble
    Commented May 22, 2013 at 1:30

To address the second question - where would new bidding systems come from if all players were required to play the same system? How would one enforce that?

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    I don't know - maybe if everyone is supposed to know exact meaning of every possible bid in any case then just use some kind of explicit protocol, without artifical rules? Current status looks a bit akward - "system must be fully disclosed including defense against it". I don't like such artificiality - such rules are "hard" to describe within concise game mechanics.
    – qble
    Commented May 22, 2013 at 0:39
  • @qble: Why are you presenting this XY problem? What issue is really at hand? Commented Jun 17, 2013 at 11:37
  • @qble: There may be a misunderstanding here. You are required to disclose how you defend against specified conventions (since that involves you making artificial bids) but not how other people can/should defend against yours. Commented Oct 7, 2013 at 16:51
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    @TimLymington: Actually, in many event classes a suggested defence must also be provided, for any particularly unusual agreements. See the ACBL SuperChart on page 3 here: acbl.org/assets/documents/play/Convention-Chart.pdf Commented Oct 7, 2013 at 21:24
  • @PieterGeerkens: Thanks, I really did not know that. It doesn't, however, apply in Britain: ebu.co.uk/laws-and-ethics/blue-book. Perhaps 'suggested defenses' may be required but 'suggested defences' are not? :) Commented Oct 7, 2013 at 22:09

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