Merge Tournament

What it is

A merge tournament takes a set of draft documents — position papers, proposed constitutions, competing specifications — and produces a single canonical text. Drafts are seeded into a knockout bracket at random. In each round, pairs of texts meet: their two bearers negotiate a merged text in a shared editor, against a fixed deadline. Both must consent to the result. If they agree, the merged text advances, carried forward by one of the two, chosen by agreement or by lot. If the clock expires first, a coin flip selects one of the two input texts to advance intact.

Rounds halve the field until one text remains. Twenty drafts become one in five rounds; the whole process fits comfortably in half a day. The full bracket — every pairing, every scheduled time — is published before the first round begins, and the completed bracket, with every intermediate text and the discussion that produced it, remains as a permanent, explorable record.

This site provides the software that runs the event: submission, seeding, scheduling, the collaborative merge workspaces, the coin flips, and the archive. The software is open source and self-hostable, with magic-link authentication and no accounts.

When you might want one

The method suits any situation where a group must produce one authoritative document from many, and where the usual alternatives fail in familiar ways: plenary drafting sessions that reward stamina and volume; committee synthesis that launders disagreement into vagueness; voting between drafts, which discards everything in the losing texts.

It was built for constitutional conventions — a cohort of ten to thirty people, each arriving with a complete draft, needing to leave with a founding document that everyone had a hand in. But the structure is general: standards bodies reconciling competing proposals, activist groups synthesising position papers, communities drafting charters or codes of conduct, workshops that want a genuine collective artefact rather than a facilitator's summary.

Two properties distinguish it from adjacent methods. Every participant negotiates directly rather than through a facilitator or a floor debate; and every draft, including the eliminated ones, is preserved with full provenance, so the final text can be traced back through every merge to its origins.

How it runs

Participants each submit a draft document before a deadline. The system builds the bracket, seeds it uniformly at random, publishes the schedule, and from that point runs itself. Rounds open and close on the clock; breaks between rounds let everyone read the surviving texts and lobby the bearers of the next round; unresolved merges are settled by an animated coin flip. The administrator has exactly two live controls: begin, and pause. There is deliberately no discretion beyond that: no extending a round, no reassigning a pairing, no overriding a flip.

At the end you have one canonical text; the complete provenance tree, tracing it back through every merge to every original draft; all eliminated texts, preserved and attributed; every discussion thread, kept open in perpetuity as an annotation layer for future readers; and an append-only audit log, including every random seed, from which the entire tournament can be reproduced.

The theory

The design is an application of bargaining theory, and its central move is decomposition. Multilateral negotiation has no canonical solution: with three or more parties, coalitions form, cycles appear, and outcomes depend on agenda order. Bilateral negotiation is the only bargaining problem whose solution survives strategic play. The tournament therefore decomposes an n-party negotiation into n − 1 two-party negotiations, arranged on a binary tree of depth log n.

Each merge is then a Nash bargaining game whose disagreement point is a fair lottery over the two input texts. This threat point is symmetric, so neither party holds positional advantage; it is what makes stonewalling unattractive, since refusing to negotiate yields not the status quo but a gamble. Composed up the tree, the equilibrium in which nobody negotiates at all is exactly (via random seeding) uniform random dictatorship over the original drafts — the canonical strategyproof mechanism, but a bleak one. The tournament is best understood as random dictatorship plus a standing right to Pareto-improve on it by unanimous consent: every negotiated merge is a voluntary escape from a lottery both parties dislike.

The remaining machinery secures the conditions under which this works. The clock provides a finite horizon, which makes delay worthless and forecloses wars of attrition. Uniformly random seeding destroys agenda-setting power and gives every draft an equal ex-ante chance of becoming the final text.