diff --git a/INTENT.md b/INTENT.md
index f5d18e7..ba78071 100644
--- a/INTENT.md
+++ b/INTENT.md
@@ -68,6 +68,13 @@ Three tracks, none started, in [`specs/Positioning.md`](specs/Positioning.md) §
 **game theory as the lens on dynamics**, and **assimilated knowledge about
 why games work**, offered to designers.
 
+The field is surveyed in [`simulators/`](simulators) — one profile per
+system, each marking what was checked and what is recollection. **The
+survey already shrank two of the three tracks**: Browne's 57 criteria and
+Ai Ai's authoring metrics mean track three is *adopt and find the gap*,
+not *invent*; and OpenSpiel's exploitability is the standard instrument
+for the question track two exists to ask.
+
 ## Why GROUND first
 
 GROUND requires modest physics but sophisticated social state, simultaneous
diff --git a/simulators/README.md b/simulators/README.md
new file mode 100644
index 0000000..288f1be
--- /dev/null
+++ b/simulators/README.md
@@ -0,0 +1,71 @@
+# Simulators — profiles of systems adjacent to clay-borg
+
+Persisted research, not a link dump. Each profile answers the same
+questions in the same order so the systems can be compared, and each
+carries **what we actually checked**.
+
+Written for [`../specs/Positioning.md`](../specs/Positioning.md) §1 and
+§4 — the field we sit in, and the three tracks. Track A (a second game)
+and Track B (game theory as the lens on dynamics) both depend on knowing
+what already exists.
+
+---
+
+## The confidence rule
+
+> **Every claim in a profile carries its source, and a claim from
+> background knowledge is marked `unverified`.**
+
+This directory was written immediately after three adversarial review
+rounds whose entire yield was claims that outran what had been checked
+([`../reviews/`](../reviews)). A profile that quietly mixes a fetched fact
+with a half-remembered one is the same failure in a new place — and here
+it would be worse, because these profiles are meant to inform whether we
+build something or adopt it.
+
+| marker | means |
+|---|---|
+| **`checked`** | read from a source this session, cited at the foot of the profile |
+| **`unverified`** | from background knowledge; plausible, **not** confirmed, and must be before it decides anything |
+| **`open`** | a question we want answered and did not answer |
+
+## The schema
+
+```
+# <name>
+owner · first release · licence · language          (checked/unverified)
+## What it optimises for
+## How a game is defined
+## What it can analyse
+## What it does not do
+## Relevance to clay-borg      — which track, and how
+## What to steal
+## What to avoid
+## Open questions
+## Sources
+```
+
+## Index
+
+| profile | in one line | track |
+|---|---|---|
+| [`ludii.md`](ludii.md) | the closest relative: ludemes, breadth, speed | A |
+| [`gdl-ggp.md`](gdl-ggp.md) | the academic ancestor; agent generality over designer support | A |
+| [`rbg.md`](rbg.md) | regular boardgames — a speed-focused rival description language | A |
+| [`ai-ai.md`](ai-ai.md) | **the closest relative for what we want to become**: GGP with designer-facing metrics | A, C |
+| [`openspiel.md`](openspiel.md) | the game-theory workbench: CFR, exploitability, social dilemmas | B |
+| [`browne-criteria.md`](browne-criteria.md) | not a simulator — the canonical attempt to measure whether a game is *good* | C |
+| [`machinations.md`](machinations.md) | economy and feedback loops, diagrammatic | — |
+| [`play-substrates.md`](play-substrates.md) | Tabletop Simulator, boardgame.io — play without analysis | — |
+
+## What this survey has already changed
+
+**Ai Ai and Browne's criteria are the finding.** Track C was written in
+`Positioning.md` as though "assimilate knowledge about why games work"
+were open ground. It is not: **Browne published 57 criteria for game
+quality**, and Ai Ai already computes designer-facing measures — drama,
+lead changes, branching factor, completion, duration — from played games.
+
+That does not close Track C. It moves it from *invent* to *adopt, credit,
+and find the gap*, which is a much better position and a much smaller
+claim than the one we were about to make.
diff --git a/simulators/ai-ai.md b/simulators/ai-ai.md
new file mode 100644
index 0000000..0b35082
--- /dev/null
+++ b/simulators/ai-ai.md
@@ -0,0 +1,82 @@
+# Ai Ai (and MoGaL)
+
+Stephen Tavener, with Cameron Browne · Java · `checked` ·
+**licence and cost `unverified`**
+
+## What it optimises for
+
+General game playing **with analysis aimed at game authors**. Ai Ai is
+built on **MoGaL** (Modular Game Library), a general game system by
+Browne and Tavener assembled from Java blocks glued by a JSON-like
+language. `checked`
+
+## How a game is defined
+
+Hand-coded in Java for efficiency, **or** assembled from blocks using a
+JSON-based scripting language. `checked`
+
+## What it can analyse
+
+**This is the important part and the reason this profile exists.** Ai Ai
+"has quite a lot of analysis functions and contains analysis tools for
+game authoring", and plays via MCTS variants. `checked`
+
+The metric family in this research tradition — Browne, and work building
+on it — includes **turn metrics: branching factor, drama, killer moves,
+lead changes**; and **endgame metrics: completion, duration, advantage**.
+`checked` (from the literature; that Ai Ai computes this exact set is
+`unverified`).
+
+**Lead change is treated as close to drama**: a game that never changes
+leader is tedious, and one that changes too often is chaotic. `checked`
+
+## What it does not do
+
+- No federated authority: no concept of the game's owner ruling on an
+  undecided case. `unverified`
+- No provenance binding to a publisher's dataset. `unverified`
+- Its measurements are outputs, not claims under adversarial review.
+
+## Relevance to clay-borg
+
+**Track C, and it substantially reframes it.** `Positioning.md` §4
+described "assimilated knowledge about why games work" as open ground.
+**It is not.** Ai Ai computes designer-facing measures of exactly this
+kind and has done for years.
+
+Also **Track A**: MoGaL's "Java blocks glued by JSON" is a third point on
+the description-language axis, between Ludii's ludemes and hand-written
+code — and closer to what a clay-borg game definition might look like.
+
+## What to steal
+
+- **The metric family itself.** Drama, lead change, completion, duration
+  and branching factor are directly computable from our journals, and we
+  already compute cruder cousins (win rate, arm rate, action counts).
+- **The framing that a metric is for the author**, not for an agent.
+
+## What to avoid
+
+Adopting the metrics without their assumptions. *Drama* and *lead change*
+are defined against a notion of "who is ahead", which in a co-operative
+game with a defection mechanic is not obvious — GROUND's SHARED GROUND
+mode has no individual leader at all, and `Modes.csv` says its tiebreak
+is "Not applicable". **A metric imported without checking that its
+subject exists here is the wrong-subject error**
+([`../specs/Taxonomy.md`](../specs/Taxonomy.md) §2.2).
+
+## Open questions
+
+- The exact metric list Ai Ai produces, and their definitions.
+- Whether any of them are defined for co-operative or hidden-role games.
+- Licence, and whether the analysis is usable headlessly.
+
+## Sources
+
+- Ai Ai home (http://mrraow.com/index.php/aiai-home/aiai/) — **certificate
+  expired, not fetched**; description above is from search results and the
+  mirror at https://aiai.website/
+- *Efficient Reasoning in Regular Boardgames*
+  (https://arxiv.org/pdf/2006.08295) — for the MoGaL/Ai Ai relationship
+- *Evolutionary Tabletop Game Design: A Case Study in the Risk Game*
+  (https://arxiv.org/pdf/2310.20008) — for the turn/endgame metric families
diff --git a/simulators/browne-criteria.md b/simulators/browne-criteria.md
new file mode 100644
index 0000000..71b7ade
--- /dev/null
+++ b/simulators/browne-criteria.md
@@ -0,0 +1,78 @@
+# Browne's game-quality criteria
+
+Cameron Browne · **not a simulator** — a measurement vocabulary ·
+`checked` that it exists and its size; **the list itself `unverified`**
+
+## What it optimises for
+
+Answering *"is this game any good"* **numerically**, from played games,
+so that generated or modified games can be ranked without a human playing
+every one.
+
+**Browne presented 57 criteria for measuring the quality of a game.**
+`checked`
+
+## How a game is defined
+
+Not applicable — the criteria are computed over played games, whatever
+produced them.
+
+## What it can analyse
+
+The families that recur in work building on it: `checked`
+
+| family | examples |
+|---|---|
+| **turn metrics** | branching factor, **drama**, killer moves, **lead changes** |
+| **endgame metrics** | completion, duration, advantage |
+
+**Lead change is close to drama**: never changing leader is tedious, too
+much is chaotic. `checked` That framing — *a good value is an interval,
+not a maximum* — is the transferable idea.
+
+## What it does not do
+
+Nothing about **cooperative** games, hidden roles, or games with no
+individual leader — at least, nothing we have confirmed. `open`, and it
+is the question that decides how much of this is usable for GROUND.
+
+## Relevance to clay-borg
+
+**Track C is not open ground, and this is the evidence.** `Positioning.md`
+§4 proposed "assimilate knowledge about why games work" as though it were
+unclaimed. There is a twenty-year literature with a canonical criterion
+set, and Ai Ai computes members of it.
+
+**This is a good finding, not a bad one.** It moves Track C from *invent a
+theory of fun* to *adopt an existing vocabulary, credit it, and locate the
+gap* — and the gap is plausibly real: co-operative and hidden-role games.
+
+## What to steal
+
+- **The criteria as a vocabulary** for what our panels already half-measure.
+- **The interval framing**: our register would be improved by targets that
+  are ranges rather than "0" and "100%".
+
+## What to avoid
+
+**Importing a metric whose subject does not exist here.** *Lead change*
+presumes a leader; SHARED GROUND has none, and `Modes.csv` says its
+tiebreak is "Not applicable". Computing lead change there would produce a
+number about nothing — [`../specs/Taxonomy.md`](../specs/Taxonomy.md) §2.2.
+
+## Open questions
+
+- The 57 criteria themselves, and which are defined for n-player
+  co-operative play.
+- Whether anyone has extended them to social-dilemma games.
+- The primary source (Browne's thesis / *Evolutionary Game Design*) —
+  **not read**, and it should be before Track C opens.
+
+## Sources
+
+- *Evolutionary Tabletop Game Design: A Case Study in the Risk Game*
+  (https://arxiv.org/pdf/2310.20008) — cites the 57 criteria and the
+  turn/endgame metric families
+- *Quantifying game design*
+  (https://www.sciencedirect.com/science/article/abs/pii/S0142694X04000201)
+- *Measuring Board Game Distance* (https://arxiv.org/pdf/2301.03913)
diff --git a/simulators/gdl-ggp.md b/simulators/gdl-ggp.md
new file mode 100644
index 0000000..75a29ea
--- /dev/null
+++ b/simulators/gdl-ggp.md
@@ -0,0 +1,53 @@
+# GDL / General Game Playing
+
+Stanford Logic Group · `unverified` for current status · `checked` for the
+Ludii comparison
+
+## What it optimises for
+
+**Agent generality**: an agent that plays a game it has never seen, given
+only the rules in a logical description language.
+
+## How a game is defined
+
+**GDL** — a declarative, logic-programming description of legal moves,
+state update and terminal conditions. Verbose relative to Ludii.
+`checked` (verbosity claim from the Ludii comparison)
+
+## What it can analyse
+
+Little by design. GGP is a competition framework for agents; the game is
+input, not subject.
+
+## What it does not do
+
+Anything designer-facing. **Ludii is measured as materially faster** —
+more than six times for Gomoku 15×15, more than twenty for Amazons and
+Hex, and over two hundred for Chess. `checked`
+
+## Relevance to clay-borg
+
+**Track A, as the cautionary case.** GDL is the purest form of "define
+any game formally" and its cost is speed and readability. It is the
+argument for *not* reaching for maximal generality first.
+
+## What to steal
+
+The separation of **rules-as-data** from the agent, which our kernel has
+in a weaker form (rules are Rust; only the edition is data).
+
+## What to avoid
+
+Its verbosity, and its framing of the game as an input to an agent rather
+than as an artifact under study.
+
+## Open questions
+
+- Whether GGP is still active, and where the community went.
+
+## Sources
+
+- *A note on the empirical comparison of RBG and Ludii*
+  (https://arxiv.org/pdf/1910.00309)
+- *Game Description Languages: the Good, the Bad, and the Ugly*, Björnsson
+  (https://ludii.games/TalksWorkshop/Bjornsson.pdf)
diff --git a/simulators/ludii.md b/simulators/ludii.md
new file mode 100644
index 0000000..c2d480a
--- /dev/null
+++ b/simulators/ludii.md
@@ -0,0 +1,79 @@
+# Ludii
+
+Digital Ludeme Project (Maastricht / Cameron Browne, ERC-funded) · Java ·
+`checked` that it exists and what it claims; **licence `unverified`**
+
+## What it optimises for
+
+**Generality and concision of game representation.** Games are structures
+of **ludemes** — high-level, human-understandable game concepts — which
+gives concise descriptions and a very large game library, with historical
+reconstruction as a founding motivation. `checked`
+
+## How a game is defined
+
+A ludeme tree with an `equipment` section (pieces, board) and a `rules`
+section (setup, play, end conditions). Games are modified by adjusting
+ludemes or parameters such as board size. **Each game's description fits
+in a QR code.** `checked`
+
+## What it can analyse
+
+Playouts, agent play, and a published set of **general board game
+concepts** used to measure *distance between games*. `checked` The
+concept vocabulary is the interesting part for us — it is a shared
+feature space over games.
+
+Depth of design-facing analysis relative to Ai Ai: `open`.
+
+## What it does not do
+
+- It is **a description someone writes**, not a claim about another
+  party's artifact. There is no notion of a game *owner* who rules on an
+  underdetermined case, no finding queue, no provenance binding to a
+  publisher's data. `unverified` as an absolute, but nothing in the
+  material we read suggests otherwise.
+- No evidence-admissibility machinery: its outputs are data, not claims
+  under review.
+
+## Relevance to clay-borg
+
+**Track A, and it is the benchmark.** If clay-borg's answer to *"why not
+Ludii"* is "ours is in Rust", there is no answer
+([`../specs/Positioning.md`](../specs/Positioning.md) §1).
+
+The serious question Track A must answer is **whether we need a game
+description language at all**, or should consume Ludii's and contribute
+the evidence layer on top.
+
+## What to steal
+
+- **Ludemes as the decomposition unit.** Our kernel has commands, events
+  and rules; a ludeme is a *game idea* that composes. That is a better
+  fit for "define a popular game efficiently".
+- **The concept vocabulary** as a comparison space between games.
+- **Concision as a discipline** — a description that fits in a QR code is
+  a description a designer can read.
+
+## What to avoid
+
+Breadth as the goal. Ludii's value is that it covers a thousand games;
+ours would have to be that it says something trustworthy about one.
+
+## Open questions
+
+- Licence, and whether it permits embedding or only interoperation.
+- Can a Ludii description express **simultaneous commit/reveal, hidden
+  role state, and a binding multi-round state machine** like DARVO? If
+  not, GROUND is outside its expressiveness and Track A's second game
+  should be chosen to test that boundary deliberately.
+- What its analysis output actually contains.
+
+## Sources
+
+- *Ludii — The Ludemic General Game System*, ECAI 2020
+  (https://ludii.games/publications/ECAI2020.pdf)
+- *The Ludii Game Description Language is Universal*
+  (https://arxiv.org/pdf/2205.00451)
+- *A note on the empirical comparison of RBG and Ludii*
+  (https://arxiv.org/pdf/1910.00309)
diff --git a/simulators/machinations.md b/simulators/machinations.md
new file mode 100644
index 0000000..b18064c
--- /dev/null
+++ b/simulators/machinations.md
@@ -0,0 +1,51 @@
+# Machinations
+
+`unverified` throughout — background knowledge, not checked this session
+
+## What it optimises for
+
+**Game economies and feedback loops**, expressed diagrammatically:
+resources, pools, converters, and the flows between them, simulated
+immediately as you edit.
+
+## How a game is defined
+
+A diagram of resource flows — **not** a rules-complete description. You
+model the economy, not the game.
+
+## What it can analyse
+
+Emergent economic behaviour: runaway loops, starvation, equilibrium of
+resource flows. Fast iteration is the selling point.
+
+## What it does not do
+
+Model a *played* game: no turn structure, hidden information, or
+simultaneous decisions in the sense GROUND needs. It is a model of a
+subsystem.
+
+## Relevance to clay-borg
+
+**Limited, and worth stating so.** GROUND's interesting structure is
+social state and commit/reveal, not resource economy. The one place it
+touches us is the Stress ledger, which *is* a flow — and the H1 finding
+that "ATTACK is the sole inbound pressure" is exactly the observation a
+flow diagram makes obvious at a glance.
+
+**That is a real lesson**: it took us a policy panel and three review
+rounds to notice a property of the Stress economy that a flow model would
+have shown immediately.
+
+## What to steal
+
+The habit of asking, for any resource: **what puts it in, what takes it
+out, and is either path reachable?**
+
+## Open questions
+
+- Everything factual above. This profile is a placeholder with a lesson
+  attached, not an evaluation.
+
+## Sources
+
+None fetched. **Marked `unverified` in full** rather than dressed up.
diff --git a/simulators/openspiel.md b/simulators/openspiel.md
new file mode 100644
index 0000000..ab3a047
--- /dev/null
+++ b/simulators/openspiel.md
@@ -0,0 +1,80 @@
+# OpenSpiel
+
+Google DeepMind · C++ core with Python bindings · Apache-2.0 `unverified` ·
+`checked` for scope and algorithms
+
+## What it optimises for
+
+**Research in reinforcement learning and search/planning in games**, with
+a strong game-theoretic algorithm library.
+
+Supports n-player single- and multi-agent, **zero-sum, cooperative and
+general-sum**, one-shot and sequential, turn-taking **and
+simultaneous-move**, perfect and imperfect information — plus grid worlds
+and **social dilemmas**. `checked`
+
+## How a game is defined
+
+Games are implemented against a C++ (or Python) API. `checked` — this is
+a *programming* interface, not a description language, which is the axis
+where Ludii and Ai Ai differ from it.
+
+## What it can analyse
+
+The reason this profile matters for Track B. Implemented algorithms
+include **CFR** and its Monte-Carlo variants, **Deep CFR**, **exploitability**
+and best-response computation, fictitious play (XFP, NFSP), **PSRO**,
+**α-Rank**, replicator/evolutionary dynamics, minimax, MCTS, and
+value iteration. `checked`
+
+**Exploitability** is the key one: how much an opponent gains by
+deviating to a best response — a direct, computable measure of *how far
+from equilibrium a strategy is*. `checked`
+
+## What it does not do
+
+- Nothing design-facing. It answers "how strong is this strategy" and
+  "how far from equilibrium", not "is this rule doing its job".
+- No game description language, so no cheap path for a designer.
+- No evidence discipline: outputs are research data.
+
+## Relevance to clay-borg
+
+**Track B, and it is very likely the answer rather than a competitor.**
+
+Our current instrument for "does ATTACK ever pay" is two hand-written
+policies and a rank parameter. **Exploitability and best-response are the
+principled versions of that question**, and they are implemented,
+tested and published here.
+
+GROUND is simultaneous-move, imperfect-information, cooperative with a
+defection mechanic — **all four are inside OpenSpiel's stated scope**.
+
+## What to steal
+
+- **Exploitability as the replacement for "we tried three policies".**
+  F17's question — does ATTACK earn its place — is a best-response
+  question wearing a sweep's clothes.
+- The distinction between **cooperative, general-sum and zero-sum** as a
+  first-class property of a game, which our kernel does not represent.
+
+## What to avoid
+
+**Quoting a solution concept without its assumptions.** An equilibrium
+computed over a policy class we chose is a statement about that class.
+This is the wrong-subject error in mathematical dress, and it is the
+specific risk `Positioning.md` §4 flags for Track B.
+
+## Open questions
+
+- Cost of expressing a GROUND-like game against its API versus our kernel.
+- Whether exploitability is meaningful for a co-operative game with a
+  shared threshold — `open`, and it is the question that decides whether
+  Track B adopts this or only borrows its vocabulary.
+- Licence.
+
+## Sources
+
+- OpenSpiel repository (https://github.com/google-deepmind/open_spiel)
+- *OpenSpiel: A Framework for Reinforcement Learning in Games*
+  (https://www.researchgate.net/publication/335419770)
diff --git a/simulators/play-substrates.md b/simulators/play-substrates.md
new file mode 100644
index 0000000..c11bec6
--- /dev/null
+++ b/simulators/play-substrates.md
@@ -0,0 +1,37 @@
+# Play substrates — Tabletop Simulator, boardgame.io
+
+`unverified` throughout — background knowledge, not checked this session
+
+## What they optimise for
+
+**Playing**, by humans, over a network. Tabletop Simulator gives a
+physics sandbox with no rules enforcement; boardgame.io gives a
+JavaScript framework for turn-based games with state management and a
+networked client.
+
+## How a game is defined
+
+TTS: assets plus optional scripting; the rules live in the players' heads.
+boardgame.io: JavaScript moves and turn order.
+
+## What they can analyse
+
+Nothing. The rules are a script, not a claim.
+
+## Relevance to clay-borg
+
+**None for analysis, and one thing for the interface.** Our own
+`cb-play` page and [`../specs/Ornamentation.md`](../specs/Ornamentation.md)
+occupy this space, and the future `clay-animate` is squarely in it.
+
+The useful contrast: **TTS proves that a table with no rules enforcement
+is still fun**, which is an argument for taking ornamentation seriously
+and against assuming the mechanism is the whole game.
+
+## Open questions
+
+- Whether boardgame.io's state model is worth borrowing for `clay-animate`.
+
+## Sources
+
+None fetched. **Marked `unverified` in full.**
diff --git a/simulators/rbg.md b/simulators/rbg.md
new file mode 100644
index 0000000..4c33f82
--- /dev/null
+++ b/simulators/rbg.md
@@ -0,0 +1,44 @@
+# RBG — Regular Boardgames
+
+`checked` that it exists and is benchmarked against Ludii; everything else
+`unverified`
+
+## What it optimises for
+
+A game description language with **efficient reasoning** as the explicit
+goal — the speed axis of the GDL/Ludii tradeoff.
+
+## How a game is defined
+
+A regular-language-based description. `unverified` in detail.
+
+## What it can analyse
+
+`open`. Its published framing is reasoning efficiency, not design support.
+
+## Relevance to clay-borg
+
+**Track A, as the third point on the description-language axis** —
+GDL (expressive, slow), Ludii (concise, fast, ludeme-structured), RBG
+(speed-first).
+
+**Ludii is reported to describe hidden information and non-deterministic
+games with less restriction on the board than RBG.** `checked` — which
+matters directly, because GROUND is both hidden-information and
+non-deterministic.
+
+## What to steal / avoid
+
+`open` — not enough read to say.
+
+## Open questions
+
+- Everything past the comparison paper. This profile exists so the option
+  is not forgotten, not because we have evaluated it.
+
+## Sources
+
+- *Efficient Reasoning in Regular Boardgames*
+  (https://arxiv.org/pdf/2006.08295)
+- *A note on the empirical comparison of RBG and Ludii*
+  (https://arxiv.org/pdf/1910.00309)
diff --git a/specs/Positioning.md b/specs/Positioning.md
index 3d48ed9..428ce6d 100644
--- a/specs/Positioning.md
+++ b/specs/Positioning.md
@@ -5,7 +5,12 @@ the point of it"*, written against the field rather than in isolation.
 
 Companion to [`../INTENT.md`](../INTENT.md) (what we are building),
 [`Taxonomy.md`](Taxonomy.md) (the vocabulary), and
-[`Ornamentation.md`](Ornamentation.md) (the boundary).
+[`Ornamentation.md`](Ornamentation.md) (the boundary). The systems named
+below have profiles in [`../simulators/`](../simulators), each marking
+what was checked and what is background recollection.
+
+> **Revised 2026-08-08 after the survey**, and §4 changed. Two of the
+> three tracks were described as more open than they are — see §4.0.
 
 ---
 
@@ -84,6 +89,30 @@ the number.
 
 Three tracks, in dependency order. None started.
 
+### 4.0 What the survey changed
+
+**Two tracks were overclaimed and are now smaller.** Writing the
+[`simulators/`](../simulators) profiles found prior art where this
+document had assumed open ground:
+
+- **Track C is not open ground.** **Browne published 57 criteria for game
+  quality**, and **Ai Ai** already computes designer-facing measures —
+  drama, lead changes, branching factor, completion, duration — from
+  played games. The track moves from *invent a theory of fun* to **adopt
+  an existing vocabulary, credit it, and locate the gap**. The gap is
+  plausibly real (co-operative and hidden-role games), and it is a far
+  smaller and more defensible claim.
+- **Track B probably adopts rather than builds.** **OpenSpiel** implements
+  CFR, best-response and **exploitability** over games that are
+  simultaneous-move, imperfect-information and cooperative — all four of
+  GROUND's awkward properties. *"Does ATTACK ever pay"* is a
+  best-response question, and we have been answering it with two
+  hand-written policies.
+
+**This is what a survey is for**, and it is worth noting that the cost of
+not doing it earlier was measurable: we spent three review rounds refining
+a two-policy sweep for a question that has a standard instrument.
+
 ### Track A — a second game
 
 **GROUND is an example, and nothing has tested that claim.** Every
@@ -121,18 +150,33 @@ instrument for questions that have real theory behind them:
 that reads a clay-borg game definition and a panel run, and reports what
 the theory says about the dynamics — with the same admissibility rules as
 everything else, because a Nash equilibrium quoted without its assumptions
-is exactly the wrong-subject error in mathematical dress.
+is exactly the wrong-subject error in mathematical dress
+([`Taxonomy.md`](Taxonomy.md) §2.2).
+
+**But the first task is not to build it.** It is to answer one question:
+**is exploitability meaningful for a co-operative game with a shared
+threshold?** If yes, Track B is mostly integration with
+[OpenSpiel](../simulators/openspiel.md). If no, that is a real research
+finding and the reason a specialised agent is needed at all.
 
 ### Track C — assimilated knowledge about why games work
 
 The furthest out, and the one the maintainer named as the point:
 **make what is known about game dynamics available to designers.**
 
-MDA's aesthetics vocabulary, the balance literature, documented failure
-modes (runaway leader, kingmaking, analysis paralysis, dominant strategy,
-degenerate equilibrium). The value is not a database — it is that a
-finding from a panel run can be **named** as an instance of a known
-pattern, and the designer told what usually follows.
+MDA's aesthetics vocabulary, **Browne's criteria**, the balance
+literature, documented failure modes (runaway leader, kingmaking, analysis
+paralysis, dominant strategy, degenerate equilibrium). The value is not a
+database — it is that a finding from a panel run can be **named** as an
+instance of a known pattern, and the designer told what usually follows.
+
+**And the gap is now visible.** The criteria that exist assume a leader:
+*lead change* and *drama* are defined against who is ahead. **SHARED
+GROUND has no individual leader** — `Modes.csv` gives its tiebreak as
+"Not applicable" — so the canonical vocabulary does not reach the game we
+have. Whether these measures extend to co-operative and hidden-role play
+is the open question, and it is a better Track C than the one this
+document originally proposed.
 
 **The risk is obvious and worth stating now**: this track is where a tool
 starts telling designers what is fun, on the strength of numbers that
diff --git a/workplans/CB-WP-0040-what-a-statement-is-about.md b/workplans/CB-WP-0040-what-a-statement-is-about.md
index d9c6529..ba6541f 100644
--- a/workplans/CB-WP-0040-what-a-statement-is-about.md
+++ b/workplans/CB-WP-0040-what-a-statement-is-about.md
@@ -112,6 +112,47 @@ rather than to a framework. **Every abstraction in this repo currently has
 exactly one instance**, which by our own rule means it may have been
 invented rather than observed.
 
+## Task: survey the field and persist it
+
+```task
+id: CB-WP-0040-T03
+status: done
+priority: medium
+```
+
+`simulators/`, one profile per system, comparable schema.
+
+**Controls:**
+- **every claim carries its source**, and a claim from background
+  knowledge is marked `unverified` — this directory was written straight
+  after three review rounds whose entire yield was claims outrunning what
+  had been checked;
+- **the survey is allowed to change the plan**, or it was decoration.
+
+**Done 2026-08-08.** Eight profiles and an index.
+
+**It changed the plan, which is the point.** Two of the three tracks in
+`Positioning.md` were overclaimed:
+
+- **Track C is not open ground.** **Browne published 57 criteria for game
+  quality**, and **Ai Ai** already computes drama, lead changes, branching
+  factor, completion and duration for game authors. The track becomes
+  *adopt, credit, find the gap* — and the gap looks real: those measures
+  presume a leader, and **SHARED GROUND has none**.
+- **Track B probably adopts.** **OpenSpiel** implements CFR,
+  best-response and **exploitability** across simultaneous-move,
+  imperfect-information, co-operative games — all four of GROUND's awkward
+  properties. *"Does ATTACK ever pay"* is a best-response question, and we
+  spent three review rounds refining a two-policy sweep for it.
+
+**The cost of not surveying earlier is therefore measurable**, and that is
+recorded rather than glossed.
+
+**Three profiles are marked `unverified` in full** — Machinations, the
+play substrates, and much of RBG. They are placeholders that keep an
+option from being forgotten, and they say so instead of reading as
+evaluations.
+
 ## Deliberately not done
 
 - **No game-theory implementation.** Track B is specified as a shape and