Pursuit
Contract bridge
Bridge is the best-designed information problem I know of that you can finish in an evening.
What it is
Bidding is a constrained language. There is a small set of legal utterances, every one of them is public, and every one of them is ambiguous on its own. Both partners have to build a shared picture of two hands using only those utterances, while two opponents listen to everything and draw their own conclusions.
You cannot say what you mean. You can only make a legal call and rely on an agreed system to carry the meaning — a system the opponents also know, and are entitled to ask about.
Why it holds me
Almost every interesting property of communication under constraint is present, in a form small enough to reason about completely. The channel is narrow. The vocabulary is fixed. Meaning is conventional rather than natural, so it has to be agreed in advance and it can be misunderstood in ways that are nobody’s fault. And everything you tell your partner, you also tell your opponents — so there is a real cost to precision, and sometimes the right move is to say less than you know.
That last property is the one I keep thinking about away from the table. A more expressive system is not automatically a better one.
TBC
How I came to bridge, and where I play
Everything else on this page is drafted. This paragraph is yours to write.
The point
What it taught me that transfers
- A shared code has to be agreed before it is needed, and the agreeing is most of the work. Systems that assume meaning is obvious fail at exactly the moments they matter.
- Information given to a partner is usually information given to everyone. Precision has a cost, and the cost is not always worth paying.
- Ambiguity is not always a defect. A signal that can carry two meanings is sometimes doing more work than two signals that each carry one.
Beginning
Where to start if you are curious
Learn to play the cards before learning to bid. Declarer play is enjoyable on its own, and it gives you the reason bidding matters — you cannot appreciate the value of an accurate auction until you have been handed a contract you had no business being in.
Then find a partner who is also learning. Bridge is unusual among games in that improvement is mostly a property of a pair rather than a person.