Why are Bridge's bid meanings public?

Question

I'm not a Bridge player, but I've been reading about the game. This part of the rules is surprising to me. From Wikipedia's article on Bridge bidding systems,

By the rules of the game, the agreed meanings of all calls must be public and known to the opponents. In normal club or home play, the opponents are entitled, at their turn to make a call, to ask the partner of the bidder about the meaning of the call. In high-level tournaments, where screens are used, the procedure is to ask the screen-mate about their calls as well as their partner's calls. In serious online tournaments, the procedure is for the player making the call to self-alert it, but the explanation is visible only to the opponents.

Why would the meaning of a bid be public information? It's unusual and seems to take away part of the preparation that would otherwise have gone into the game. For example, if meanings were secret, then they can be pre-arranged by partners and later used to deceive their opponents. Making it all public seems to detract from the strategic depth of the game. Besides, at that point, why even bother with bidding systems? Let's say the current bid is 1 NT, and I want to know whether my partner is holding the Ace of Clubs. I could just say "I bid 2 Clubs, if you are holding the Ace of Clubs bid 2 Diamonds, otherwise bid 2 Hearts".

What is the advantage to having meanings public? The only advantage I can think of is that there isn't enough scope for strategic play otherwise, but even then this rule seems very artificial.

Answer 1

Note, the agreed meanings of bids must be agreed in advance, they may not be changed on the fly. In serious duplicate play, players have a written description of their agreements available to the opponents.

This changes it from an exercise in cryptography to a problem of card play and deduction. The idea is that a players opponents will have as much knowledge about what his bids and plays mean as his partner does. They are not entitled to know what the player holds or intends, merely what his agreements are. It is also put that one may make a bid or play not according to the agreements, provided that one's partner is as surprised as ones opponents.

You may not instruct partner during the play what response is wanted for what holding -- this must be pre-arranged, and a system in which 2D showed the Ace of clubs in response to a 2C bid would fail on far too many hands.

Secret agreements provide a too-easy means to cheat, by conveying more information than open agreements allow, particularly by combining with hand-signals, body language, tone of voice, and the like. (those are still used by dishonest players, but less easily.)

It is true that ate the very top levels of play, screens prevent some of this kind of illicit information exchange, but there is a good deal of 'serious' play below the level where screens are normally used, and the standards for bridge play were set long before screens were in common use. And if bidding systems were secret, and subject to change on the fly, there could still be information exchange of a kind which many think would harm the game. Besides, a significant part of the game, especially at high levels, is the attempt to determine from the overall auction what each player holds. it can never be totally accurate, but a good player can get surprisingly close. Allowing secret unexplained bidding systems would destroy this aspect of the game. And allowing this only in top-level bridge would make that a very different game.

The question says:

For example, if meanings were secret, then they can be pre-arranged by partners and later used to deceive their opponents.

They may not be secret or used to deceive, but they are indeed prearranged. A high-level pair may spend hundreds or thousands of hours deciding on just what the meaning for each possible bidding sequence should be, and how the various possibility interact to give the best results in play. A pair with superior bidding tools may have a very large advantage over a pair with inferior tools. A sound bidding system allows a pair to reach the best contract more often, to make it harder for their opponents to reach their best contract, and to exchange information which can significantly aid in defense if the opponents win the contract.

Answer 2

Making it all public seems to detract from the strategic depth of the game.

Experience have shown this not to be the case.

Besides, at that point, why even bother with bidding systems?

Because it's far more important to know what your partners hand look like than it is to prevent your opponent from knowing what your hand looks like.

Answer 3

Bridge is different from other card games such as poker. In poker, one is playing solo, and a large part of the game is to bluff, obfuscate, and deceive the opponents.

Bridge was considered a "gentleman's" (and "ladies") game, played in partnerships. The possibility of "collusion" meant that bridge authorities bent over backward to make sure that no one would gain an "unfair" advantage in this way. It was understood that partnerships might have their own "ways" that differed from conventional rules, but this would always be disclosed to create a level playing field. In theory, everyone would have an equal opportunity to learn everyone else's systems, although in practice partnerships practiced in a proprietary system might have an advantage, even if fully disclosed.

Bridge prided itself on attracting a better class of people than poker, and while "deception" is permitted within the laws of bridge (you need not volunteer information), it also must be done in a "legally accurate" manner (within the context of the game).