v0.8.0.14 — the coaches that never come back, and a district that ends at its own sign

Six reports from the Day 2-3 playtest of v0.8.0.13.

GAMES IN PROGRESS DO NOT SURVIVE THIS ONE. Modifiers are now bounded by the
Limits, which makes a once-legal move illegal, so a save holding one is refused
at that move: whistle-6945.day3.stage10 stops at intent 528 of 539. Jesse's call,
knowing it strands the game on the box. The file is untouched and v0.8.0.13
still finishes it.

The Sparrow running empty and Tom unable to unload his passengers are the same
shortage from opposite ends, and both are the rules working as printed. §9.2
boarding discards the emptied coach into the CLASSIFICATION yard, detraining
draws a fresh empty out of the DIVISION yard, and §2.2 sends Classification back
only when the Division Yard runs bare — so coaches move one way. Measured over
the save: sixteen in the Division Yard at setup, zero from Day 2 Stage 8 to the
end, fifteen piled in Classification, the Division Yard steady at 46-47 freight
cars with no prospect of going bare. Jesse's ruling is Gitea#2's: the shortage
stays and the game says so. A train made up short now reports what its card
wanted and why none is coming (`makeUpShort` — `trainNeedingCars` answered null
for "done" and for "cannot be done" alike, so the phase moved on in silence); the
yard panel warns while the condition lasts; the Depot's blocked panel was right
all along.

The modifier outside the Limits was working as designed and the design was
Jesse's own call, now reversed. What decided it is what the board shows — a card
beyond your own sign, in territory §8.1 and §10 reason about. The case that
motivated the exemption was checked on the reported move rather than argued away:
the Power Plant sat at (-1,3) against a sign at column 3 and two spots inside
were free, legal and adjacent.

Switching filled the history with coordinates — a line per move, plus one per
mandatory coupling. It is still LOGGED in full; what the panel draws is the line
saying somebody switched, the first move, work at an INDUSTRY (named, not a
coordinate), the Small Yard sort, and a closing summary. The suppressed lines are
still WRITTEN, marked `trace`: dropping them outright was the first attempt and
the step-queue suite caught it, because dwellForStep pays nothing for a step that
said nothing, so the board stopped replaying switching at all. The last move
rides in the closing line rather than being kept in place — nothing knows a move
was the last until the turn is over, by which time the line has been streamed to
every client and cannot be revised. Two things fell out of reading those lines:
every move ended with a tutorial sentence the opener already gives, and the move
count said "of 6" with the six hardcoded, which is wrong on a night Stage.

Make-up lines name their train — they all read "the train being made up", so
looking back for train 10 found nothing under that name — and "a empty tank" is
now "an empty tank". The Small Yard's options read as the train they would build
instead of `[1,2,3,0]`; the one Jesse wanted was the first of five and unreadable.
Two of those five were junk: bringing the last car to the end is the identity and
would have spent a Move, and a two-car reversal duplicated its only real option.
Both are filtered by the resulting order, not by the case that made them.

A Small Yard may now put cars AHEAD of the engine, which was Jesse's own open
question. Two sources disagreed and the design notes won: the v0.4.5 card text
says the sort puts the engine at the nose, implications.md says "any order,
including cars ahead of the engine". `engineAt` is optional on the intent, so
older saves replay to the same train. The menu did not multiply — the engine is a
separate short list against the consist as it stands, eight options for a
four-car train rather than twenty. §8.2 needed no new code: badlyMadeUp is
deliberately direction-free, so a PUSHING train is fit to run and only a
broken-backed one is held. The button warns by asking that predicate rather than
copying it, and immediately earned itself — every one of train 10's eight options
is refused, the one asked for at the table included, because that train carries a
caboose and each sort moves it off the rear. That is the right answer rather than
a gap: the train is already made up, so every offer would break it, and the labels
say which is which. A made-up order is always on the menu for a train that needs
one, because "bring car k to the tail" is enumerated for every car and the caboose
is one of them.

Labels read WEST TO EAST, with the engine drawn as the board's own ◀ / ▶ arrow.
"Front to back" is not a direction a table can read — which end is the front
depends on which way the train points — and board-svg has reversed east-facing
consists since v0.8.0, so the button now describes the same train as the picture.

The Freight Agent, Porter and Laborer groups now say what the role is for, where
the role is chosen. Tom reached for the Freight Agent to detrain passengers,
which is a Porter's action in the Cargo phase; both halves were working and
neither was visible.

TODO closes #107 (the nose sort) and gains #108 (the coach ratchet, with the
measurement, to revisit on a second game's data).

999 fast tests and 35 sim tests pass.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DmdqqCNoiqE7GBo6wthBnR

src/engine/advance.ts

@@ -31,12 +31,13 @@ import {
   houseRules,
   officeProfile,
   mainlineProfile,
+  consistSize,
 } from './content.ts';
-import type { Direction, MainlineEntry, MainlineKind } from './content.ts';
+import type { CarType, Direction, MainlineEntry, MainlineKind } from './content.ts';
 import type { GameEvent } from './events.ts';
 // `trainNeedingCars` lives in apply.ts beside `check`'s copy of the same question, so the phase and
 // the legality test cannot disagree about which train is being assembled.
-import { areaAtSeat, areaOf, occupancyFor, trainNeedingCars } from './apply.ts';
+import { acceptsCar, areaAtSeat, areaOf, isBeingMadeUp, occupancyFor, trainNeedingCars } from './apply.ts';
 import { legalActions } from './legal.ts';
 import type { CrewTray, DivisionNode, GameState, GridCoord, Outcome, PlayerIndex, RollingStock, SeatIndex, TrayId } from './state.ts';
 import { cloneTally, coordKey, freshTurns, isExtendable, playerAtSeat, playerLeftOf, pooled, railFacingOf, subdivisions, totalRevenue, turnOf } from './state.ts';
@@ -393,6 +394,45 @@ function newTrainPhase(s: GameState, events: GameEvent[]): AdvanceResult {
     return { events, needsInput: true };
   }
 
+  /**
+   * SAY SO WHEN A TRAIN GOT NOTHING, before the round is over and the train runs (playtest,
+   * 2026-09-16: "train 5, the sparrow, has no coaches, which seems strange").
+   *
+   * `trainNeedingCars` returns null both when every consist is full and when the Division Yard holds
+   * nothing a short train will take — the same answer for "done" and for "cannot be done" — so the
+   * phase moved on in silence and the only trace was a MADE UP line promising "now taking cars". The
+   * Sparrow calls for three coaches and left empty twice in one game.
+   *
+   * REPORTED HERE RATHER THAN AT THE MADE-UP MOMENT, because a train made up early in the round can
+   * still be filled by a later placement; only once the round has nothing left to offer is the
+   * shortfall a fact. This is reached exactly once per Stage — the next line enters the Mainline
+   * Phase — so the report cannot repeat.
+   */
+  for (const tray of s.trays.values()) {
+    if (!isBeingMadeUp(tray) || tray.trainNumber === null) continue;
+    const profile = trainProfile(tray.trainNumber, tray.trainIsExtra);
+    if (!profile) continue;
+    const category = (t: CarType): 'freight' | 'coach' | 'caboose' =>
+      t === 'coach' ? 'coach' : t === 'caboose' ? 'caboose' : 'freight';
+    // What the card still wants: asked of `acceptsCar` per category, so a full category and a
+    // category barred by the card's own rules answer the same way here as they do to a player.
+    const missing = (['freight', 'coach', 'caboose'] as const).filter((cat) => {
+      const sample: CarType = cat === 'coach' ? 'coach' : cat === 'caboose' ? 'caboose' : 'boxcar';
+      return acceptsCar(tray, sample);
+    });
+    if (missing.length === 0) continue;
+    events.push({
+      type: 'makeUpShort',
+      trainNumber: tray.trainNumber,
+      isExtra: tray.trainIsExtra,
+      placed: tray.consist.length,
+      wanted: consistSize(profile.consist),
+      missing: [...missing],
+      waiting: s.yards.classificationYard.filter((c) => missing.includes(category(c.type))).length,
+      divisionYardHolds: s.yards.divisionYard.length,
+    });
+  }
+
   return { events: [...events, ...enterPhase(s, 'mainline')], needsInput: false };
 }
 
@@ -544,7 +584,7 @@ export function badlyMadeUp(tray: CrewTray): string | null {
   const pulling = tray.engineAt === 0;
   const pushing = tray.engineAt === n;
   if (!pulling && !pushing) {
-    return `not made up — the engine is buried in the train, ${tray.engineAt} car(s) ahead of it`;
+    return `not made up — the engine is buried in the train, ${tray.engineAt} car${tray.engineAt === 1 ? '' : 's'} ahead of it`;
   }
   const caboose = tray.consist.findIndex((c) => c.type === 'caboose');
   if (caboose === -1) return null;

src/engine/apply.ts

@@ -974,6 +974,16 @@ export function check(s: GameState, player: PlayerIndex, i: Intent): RejectionCo
       const seen = new Set(i.order);
       if (seen.size !== i.order.length) return 'CONSIST_ORDER';
       if (i.order.some((n) => n < 0 || n >= tray.consist.length)) return 'CONSIST_ORDER';
+      /**
+       * The engine may finish anywhere in the train, including with cars ahead of it (Jesse,
+       * 2026-09-17). `engineAt` indexes the SORTED consist, so `consist.length` is legal and means
+       * the engine on the tail with everything ahead of it — the shoving case a Small Yard exists to
+       * set up. Refused outside that range rather than clamped: a clamp would silently build a
+       * different train from the one the player asked for.
+       */
+      if (i.engineAt !== undefined && (i.engineAt < 0 || i.engineAt > tray.consist.length)) {
+        return 'CONSIST_ORDER';
+      }
       return null;
     }
 
@@ -1426,17 +1436,30 @@ function checkPlay(
       if (!placement) return 'NO_PLACEMENT';
       if (area.grid.has(coordKey(placement))) return 'NOT_CONNECTED';
       /**
-       * NOT ON THE RUNNING TRACK ROW — AND NOT BOUNDED BY THE LIMITS EITHER. Jesse's call, both
-       * halves.
+       * NEITHER ON THE RUNNING TRACK ROW NOR OUTSIDE THE LIMITS — Jesse's call, both halves, the
+       * second REVERSED on 2026-09-17 after a Day 3 playtest.
        *
-       * A Modifier is not track (§9), so unlike a siding it may hang outside the Limits: a Facility
-       * standing at the limit has three of its nine spots out there, and refusing them would make
-       * the card unplayable exactly where the district ends. What it may NOT do is stand in the row
-       * the Running Track grows along. Inside the Limits that row is always full, so this bites only
-       * beyond the sign — which is the ground the main extends onto, and a Modifier parked there
-       * would block your own sign from moving outward (§2.1) with nothing on screen to warn you.
+       * It used to read the other way: a Modifier is not track (§9), so unlike a siding it could
+       * hang outside the Limits, because a Facility standing at the limit has three of its nine
+       * spots out there and refusing them would make the card unplayable exactly where the district
+       * ends. What that argument missed is what the board then shows — Transmission Lines at (-2,4)
+       * with the sign at column 3 — which reads as building outside your own territory, and §8.1 and
+       * §10 both reason about what lies inside a player's Limits.
+       *
+       * THE UNPLAYABLE CASE WAS CHECKED ON THE REPORTED MOVE, not assumed away: the Power Plant was
+       * at (-1,3) against a sign at column 3, and (-2,2) and (-2,3) were free, legal and inside. Six
+       * of the nine spots survive a Facility at the limit, and the sign moves outward as the Running
+       * Track grows (§2.1, Gap 4a), so the ground arrives with the district.
+       *
+       * The Running Track row stays barred for its own reason: inside the Limits that row is always
+       * full, so it bit only beyond the sign, where a Modifier would block the sign from moving
+       * outward with nothing on screen to warn you. That ground is now out of bounds anyway, which
+       * makes this the narrower rule rather than a redundant one — the row is barred INSIDE the
+       * Limits too, where a square can fall vacant if the main is rebuilt around it.
        */
       if (placement.row === area.runningRow) return 'ON_RUNNING_TRACK';
+      // §2.1 — a district's cards belong inside its own sign, Modifiers included since 2026-09-17.
+      if (!withinLimits(area, placement)) return 'OUTSIDE_LIMITS';
       // One of a kind per Office Area, as with industries (Q4) — no district gets two Ice Houses.
       if (hasModifierInArea(area, card.kind.modifier)) return 'FACILITY_LOCKED';
       // §9 — a Modifier is not track. It must sit adjacent to a Facility THAT CAN HOST IT (one of
@@ -1680,6 +1703,9 @@ function execute(s: GameState, player: PlayerIndex, i: Intent): GameEvent[] {
           from,
           to: i.to,
           movesRemaining: turnOf(s, player).movesRemaining - 1,
+          // "3 of 6" was written with the 6 hardcoded in the narrator, which is wrong on a night
+          // Stage under Reduced Visibility, where a turn gets five. The turn knows; the event carries.
+          movesAllowed: turnOf(s, player).movesAllowed,
           /**
            * A TRAIN THAT BACKS UP HAS NOT TURNED AROUND — AND A CURVE IS NOT A STRAIGHT.
            *
@@ -1775,11 +1801,29 @@ function execute(s: GameState, player: PlayerIndex, i: Intent): GameEvent[] {
           at: here,
           before: tray.consist.map((c) => ({ ...c })),
           after: i.order.map((n) => ({ ...tray.consist[n]! })),
+          // Absent means the nose, which is what every sort did before 2026-09-17 — so an older save
+          // replays to exactly the train it built.
+          engineAt: i.engineAt ?? 0,
         },
       ];
     }
 
-    case 'switch.end':
+    /**
+     * The closing summary comes BEFORE `phaseEnded`, so the history reads as the turn ending rather
+     * than as a postscript to it. Split out of the shared case below for that one line.
+     */
+    case 'switch.end': {
+      const turn = turnOf(s, player);
+      const ended: GameEvent = {
+        type: 'switchingEnded',
+        player,
+        movesUsed: turn.movesAllowed - turn.movesRemaining,
+        movesAllowed: turn.movesAllowed,
+        ...(turn.lastMove ? { lastMove: turn.lastMove } : {}),
+      };
+      return [ended, { type: 'phaseEnded', player, phase: 'localOps' }];
+    }
+
     case 'draw.end':
     case 'freightAgent.end':
       return [{ type: 'phaseEnded', player, phase: 'localOps' }];
@@ -1956,18 +2000,41 @@ function execute(s: GameState, player: PlayerIndex, i: Intent): GameEvent[] {
       ];
     }
 
-    case 'newTrain.placeCar':
+    /**
+     * THE TRAIN'S NUMBER RIDES ALONG (playtest, 2026-09-16: "I did not see anything in the history
+     * about making up train 10 and how each person added each car to it").
+     *
+     * It was all there — a MADE UP line and one line per car — but every one of those lines read
+     * "the train being made up", so a player scanning the history for train 10 found nothing under
+     * that name. The tray id is no use to a reader and the narrator has no state to look it up in,
+     * so the number travels with the event, exactly as `owner` does on `trainArrived`.
+     */
+    case 'newTrain.placeCar': {
+      const placeTray = s.trays.get(i.trayId);
       return [
         {
           type: 'carPlacedOnTrain',
           player,
           trayId: i.trayId,
           stock: { type: i.carType, loaded: i.loaded },
+          trainNumber: placeTray?.trainNumber ?? null,
+          isExtra: placeTray?.trainIsExtra ?? false,
         },
       ];
+    }
 
-    case 'newTrain.passCar':
-      return [{ type: 'carPassed', player, trayId: i.trayId }];
+    case 'newTrain.passCar': {
+      const passTray = s.trays.get(i.trayId);
+      return [
+        {
+          type: 'carPassed',
+          player,
+          trayId: i.trayId,
+          trainNumber: passTray?.trainNumber ?? null,
+          isExtra: passTray?.trainIsExtra ?? false,
+        },
+      ];
+    }
 
     case 'newTrain.secondSection':
       return [{ type: 'secondSectionOrdered', player, trainNumber: i.trainNumber }];
@@ -2141,7 +2208,10 @@ export function reduce(s: GameState, e: GameEvent): void {
       }
       // Only the player sitting in this district can be switching this tray, so the Moves come off
       // their turn. The event carries no player of its own.
-      turnOf(s, playerAtSeat(s, seat)).movesRemaining = e.movesRemaining;
+      const mover = turnOf(s, playerAtSeat(s, seat));
+      mover.movesRemaining = e.movesRemaining;
+      // Where the crew was left, for the line that closes the turn — see `switchingEnded`.
+      mover.lastMove = { trayId: e.trayId, to: e.to };
 
       const area = areaAtSeat(s, seat);
 
@@ -2219,9 +2289,18 @@ export function reduce(s: GameState, e: GameEvent): void {
     case 'consistSorted': {
       const tray = s.trays.get(e.trayId)!;
       tray.consist = e.after.map((c) => ({ ...c }));
-      // A Small Yard re-makes the train, and putting the engine back on the nose is the whole reason
-      // to use one: §8.2 will not let a train leave the Office with cars in front of its engine.
-      tray.engineAt = 0;
+      /**
+       * WHERE THE SORT PUT THE ENGINE — 0 on every sort before 2026-09-17, and on most of them
+       * since, because putting the engine back on the nose is what a Small Yard is usually for:
+       * §8.2 will not let a train leave the Office with cars in front of its engine.
+       *
+       * It is no longer forced. The design source (`implications.md`) has always said a train here
+       * "may sort itself into any order, INCLUDING cars ahead of the engine", against a v0.4.5 card
+       * text that says the engine ends at the nose; Jesse settled it for the source. A numbered
+       * train left nose-loaded is held at the Office by §8.2 until it sorts again — see
+       * `departureRefusal`.
+       */
+      tray.engineAt = e.engineAt;
       // "Spends one move in the yard" — the sort costs a Move.
       const sorter = turnOf(s, playerAtSeat(s, trayySeat(tray)));
       sorter.movesRemaining = Math.max(0, sorter.movesRemaining - 1);

src/engine/events.ts

@@ -46,7 +46,7 @@ export type GameEvent =
    * more than one legal route to `to`, so the history can say which one ran rather than leaving a
    * choice the player made invisible in their own log.
    */
-  | { type: 'trayMoved'; player: PlayerIndex; trayId: TrayId; from: GridCoord; to: GridCoord; movesRemaining: number; facing?: 'n' | 's' | 'e' | 'w'; via?: GridCoord }
+  | { type: 'trayMoved'; player: PlayerIndex; trayId: TrayId; from: GridCoord; to: GridCoord; movesRemaining: number; movesAllowed: number; facing?: 'n' | 's' | 'e' | 'w'; via?: GridCoord }
   | {
       type: 'carsCoupled';
       player: PlayerIndex;
@@ -82,7 +82,39 @@ export type GameEvent =
       recoupled?: { at: GridCoord; stock: RollingStock[] };
     }
   | { type: 'carsDropped'; player: PlayerIndex; trayId: TrayId; at: GridCoord; stock: RollingStock[]; fromNose?: boolean }
-  | { type: 'consistSorted'; player: PlayerIndex; trayId: TrayId; at: GridCoord; before: RollingStock[]; after: RollingStock[] }
+  | {
+      type: 'consistSorted';
+      player: PlayerIndex;
+      trayId: TrayId;
+      at: GridCoord;
+      before: RollingStock[];
+      after: RollingStock[];
+      /**
+       * Where the engine ends up in `after`, counted as an index into it — 0 is the nose.
+       *
+       * The Small Yard used to put the engine back on the front unconditionally, which is what the
+       * v0.4.5 card text says ("reorder its entire consist and put the engine at the nose").
+       * `implications.md` records the design source saying the opposite — "may sort itself into any
+       * order, INCLUDING cars ahead of the engine" — and Jesse settled it that way on 2026-09-17.
+       */
+      engineAt: number;
+    }
+  /**
+   * A player finished their switching turn: what it cost, and where the crew was left.
+   *
+   * The history panel keeps a switching turn's FIRST move and drops the ones in the middle, so the
+   * closing line is where "and it ended up here" has to come from. It cannot be recovered by
+   * revealing the last `trayMoved` after the fact: the log streams to clients as it is written
+   * (`server/session.ts` § linesSince), and nobody knows a move was the last one until the turn is
+   * already over and that line has been sent.
+   */
+  | {
+      type: 'switchingEnded';
+      player: PlayerIndex;
+      movesUsed: number;
+      movesAllowed: number;
+      lastMove?: { trayId: TrayId; to: GridCoord };
+    }
   | { type: 'cardDrawn'; player: PlayerIndex; source: 'homeOffice' | 'department'; slot?: number; cardId: CardId }
   /**
    * §6.2 — the Home Office deck ran out, so the Salvage Yard and all three Department decks were
@@ -195,8 +227,36 @@ export type GameEvent =
       at: ExtraStart;
       direction: Direction;
     }
-  | { type: 'carPlacedOnTrain'; player: PlayerIndex; trayId: TrayId; stock: RollingStock }
-  | { type: 'carPassed'; player: PlayerIndex; trayId: TrayId }
+  | { type: 'carPlacedOnTrain'; player: PlayerIndex; trayId: TrayId; stock: RollingStock; trainNumber: number | null; isExtra: boolean }
+  | { type: 'carPassed'; player: PlayerIndex; trayId: TrayId; trainNumber: number | null; isExtra: boolean }
+  /**
+   * A train was made up and the round could give it NOTHING THE CARD CALLS FOR — the Division Yard
+   * holds no car of a category it still wants (§7, §8.2 "may depart with fewer").
+   *
+   * ITS OWN EVENT BECAUSE THE SILENCE WAS THE BUG (playtest, 2026-09-16: "train 5, the sparrow, has
+   * no coaches, which seems strange"). `trainNeedingCars` returns null in exactly this case, so the
+   * phase never stops, nobody is asked for a car, and the only trace was a MADE UP line promising
+   * "now taking cars" with nothing after it. The train then ran the whole Division empty.
+   *
+   * CARRIES WHY, not just that. The shortage is a standing condition rather than a moment — §2.2
+   * returns the Classification Yard only when the Division Yard runs bare — so the counts that
+   * explain it have to travel with the event: what is still wanted, how many such cars are waiting
+   * in Classification, and how far the Division Yard is from empty.
+   */
+  | {
+      type: 'makeUpShort';
+      trainNumber: number;
+      isExtra: boolean;
+      /** How many cars it got, out of what the card calls for. */
+      placed: number;
+      wanted: number;
+      /** The categories the card still wants and the Division Yard cannot supply. */
+      missing: ('freight' | 'coach' | 'caboose')[];
+      /** Cars of those categories sitting in the Classification Yard. */
+      waiting: number;
+      /** §2.2 — Classification comes back only when this reaches zero. */
+      divisionYardHolds: number;
+    }
   | { type: 'dispatchBonusUsed'; key: string; bonus: number; trainNumber: number; againstTrain: number }
   | { type: 'clearanceRequested'; trainId: TrayId; occupiedBy: TrayId }
   | { type: 'clearanceGiven'; trainId: TrayId; allow: boolean }

src/engine/intents.ts

@@ -47,7 +47,19 @@ export type Intent =
    * order, including cars in front of the engine". This is the designed answer to §A.3's
    * come-off-in-seated-order constraint, which is what makes facing-point work possible.
    */
-  | { type: 'switch.sortConsist'; trayId: TrayId; order: number[] }
+  /**
+   * §Enhancements, Small Yard — one Move to re-make a train standing on the yard.
+   *
+   * `order` is a permutation of the current consist, nose first. `engineAt` is where the LOCOMOTIVE
+   * ends up in it: 0 puts it back on the front, which is what the v0.4.5 card text describes and
+   * what this action did unconditionally until 2026-09-17. `implications.md` records the design
+   * source saying a train here "may sort itself into any order, including cars ahead of the engine",
+   * and Jesse ruled that way — so it is a number now, and a train left nose-loaded is one §8.2 will
+   * not let out of the Office until it is sorted again.
+   *
+   * Optional, defaulting to 0, so every save written before this replays exactly as it did.
+   */
+  | { type: 'switch.sortConsist'; trayId: TrayId; order: number[]; engineAt?: number }
   | { type: 'switch.end' }
   // -- draw (§6.2)
   | { type: 'draw.fromHomeOffice' }

src/engine/legal.ts

@@ -91,17 +91,79 @@ function switchCandidates(s: GameState, player: PlayerIndex): Intent[] {
       // that shoved a cut, and therefore the only way an engine buried mid-train reaches an end.
       out.push({ type: 'switch.dropCars', trayId, count: n, fromNose: true });
     }
-    // Small Yard: enumerating every permutation would explode, so offer the useful ones —
-    // bringing each car to the droppable end, plus a full reversal. `check` validates any order,
-    // so a UI may submit an arbitrary permutation.
+    /**
+     * Small Yard: enumerating every permutation would explode, so offer the useful ones — bringing
+     * each car to the droppable end, plus a full reversal. `check` validates any order, so a UI may
+     * submit an arbitrary permutation.
+     *
+     * NOTHING THAT RE-ORDERS NOTHING. Bringing the LAST car to the end is the identity, and a
+     * two-car train's reversal repeats its only real option — so the menu carried a move that spent
+     * one of six Moves to leave the train exactly as it was, beside a duplicate of the move next to
+     * it. Both were invisible while the labels were index lists (playtest, 2026-09-17); both are
+     * plainly wrong once the label reads as a train. Filtered by the ORDER rather than by the case
+     * that produced it, so a new generator cannot reintroduce either.
+     */
     const n = tray.consist.length;
+    const identity = [...Array(n).keys()];
     if (n > 1) {
+      const orders: number[][] = [];
       for (let k = 0; k < n; k++) {
-        const order = [...Array(n).keys()].filter((x) => x !== k);
+        const order = identity.filter((x) => x !== k);
         order.push(k);
-        out.push({ type: 'switch.sortConsist', trayId, order });
+        orders.push(order);
+      }
+      orders.push([...identity].reverse());
+      // Nothing that re-orders nothing: the current train is the one thing on offer that costs a
+      // Move and changes the board not at all. Keyed by (order, engine position) together, since
+      // since 2026-09-17 the same car order at a different engine position is a different train.
+      const seen = new Set<string>([`${identity.join(',')}|${tray.engineAt}`]);
+      const offer = (order: number[], engineAt: number): void => {
+        const key = `${order.join(',')}|${engineAt}`;
+        if (seen.has(key)) return;
+        seen.add(key);
+        out.push({ type: 'switch.sortConsist', trayId, order, engineAt });
+      };
+      // The car orders, each leaving the engine on the nose — the Small Yard's ordinary use.
+      for (const order of orders) offer(order, 0);
+      /**
+       * A MADE-UP ORDER IS ALWAYS AMONG THESE, which is worth saying because it looks as though it
+       * might not be (Jesse, 2026-09-17: "trains with a caboose have to offer the caboose at the
+       * back").
+       *
+       * A yard sort serves two errands — pulling one car out to an end so it can be spotted, and
+       * putting the train back together to leave — and the orders above are written for the first.
+       * They cover the second as a by-product: "bring car k to the tail" is enumerated for EVERY car,
+       * so bringing the CABOOSE to the tail is always one of them, and with the engine on the nose
+       * that is a train §8.2 will let out of the Office.
+       *
+       * An explicit "make it up to leave" option was written here and deleted: it produced exactly
+       * the k-is-the-caboose order and was dropped by the dedupe every time. The one case where no
+       * made-up order appears is a train that is ALREADY made up, where such an option would be the
+       * identity — and the labels say which is which, so a player can see that every offer would
+       * break a train that is currently fit to run.
+       */
+    }
+    /**
+     * WHERE THE ENGINE GOES, as its own short list rather than multiplied through the one above
+     * (Jesse's call, 2026-09-17: "a separate engine control").
+     *
+     * Offering every car order at every engine position is the honest enumeration and it is
+     * unreadable: a four-car consist would go from four options to twenty, which is the labelling
+     * problem that prompted all of this. So the engine positions are offered against the consist AS
+     * IT STANDS — pick an order, or pick where the engine sits, each one Move. A player who wants
+     * both spends two, which is the same price the yard charges for any second sort.
+     *
+     * OFFERED FOR A ONE-CAR TRAIN TOO, unlike the car orders: a single car ahead of the engine or
+     * behind it is exactly the difference between shoving it into a facing industry and pulling it.
+     */
+    if (n >= 1) {
+      const seenEngine = new Set<string>([`${identity.join(',')}|${tray.engineAt}`]);
+      for (let k = 0; k <= n; k++) {
+        const key = `${identity.join(',')}|${k}`;
+        if (seenEngine.has(key)) continue;
+        seenEngine.add(key);
+        out.push({ type: 'switch.sortConsist', trayId, order: identity, engineAt: k });
       }
-      out.push({ type: 'switch.sortConsist', trayId, order: [...Array(n).keys()].reverse() });
     }
   }
   // Flying Switch — roll a cut into an ADJACENT industry without the engine entering it.

src/engine/state.ts

@@ -875,6 +875,25 @@ export type FinalReport = {
 export type TurnState = {
   option: 'switch' | 'draw' | 'freightAgent' | null;
   movesRemaining: number;
+  /**
+   * What `movesRemaining` started at this Stage — six, or five under Reduced Visibility at night.
+   *
+   * CARRIED RATHER THAN ASSUMED. Every reader of `movesRemaining` that wanted to say "3 of 6" had
+   * hardcoded the 6, which is simply wrong on a night Stage, and the only other way to recover it is
+   * to re-derive `movesForStage` outside the phase driver that owns it. It also makes "is this the
+   * FIRST move of the turn?" a comparison rather than a guess, which is what the history panel needs
+   * to keep the opening move of a switching turn and drop the ones in the middle.
+   */
+  movesAllowed: number;
+  /**
+   * The last square this player's crew moved to this Stage, and which crew it was.
+   *
+   * Switching ends with a summary line, and "where did the train end up" is the half of it a player
+   * actually wants. It cannot be recovered from the log: the line naming the last move is written
+   * before anyone knows it was the last, and the log streams to clients as it is written, so a line
+   * already sent cannot be revised afterwards.
+   */
+  lastMove?: { trayId: TrayId; to: GridCoord };
   drawnThisTurn: boolean;
   freightAgentUsed: boolean;
   /**
@@ -1057,6 +1076,7 @@ export function freshTurn(moves: number): TurnState {
   return {
     option: null,
     movesRemaining: moves,
+    movesAllowed: moves,
     drawnThisTurn: false,
     freightAgentUsed: false,
     freightWorked: {},

src/engine/track.ts

@@ -684,10 +684,19 @@ export function carriesThroughTrack(card: TrackCard): boolean {
  * buildable column and break §11.3's promise that both Secondary rows, and the nine-spot Modifier
  * neighbourhood, are usable from the first Stage.
  *
- * MODIFIERS ARE NOT SUBJECT TO THIS, and are not track: §9 places one on any of the nine spots
- * around a Facility, and a Facility standing at the limit has three of its nine outside them.
- * Jesse's call. `check` bars them from the Running Track ROW instead, which is the ground the main
- * grows onto.
+ * MODIFIERS ARE SUBJECT TO THIS TOO, since 2026-09-17 — REVERSING an earlier call of Jesse's that
+ * exempted them. The exemption reasoned that §9 places a Modifier on any of the nine spots around a
+ * Facility, so a Facility standing at the limit has three of its nine outside them and bounding the
+ * card would make it unplayable exactly where a district ends. Play showed the cost of that the
+ * other way round: a Transmission Lines card went down at (-2,4) with the sign at column 3, which
+ * reads at the table as building outside your own territory, and §8.1 and §10 both reason about
+ * what is inside a player's Limits.
+ *
+ * THE FEARED CASE DID NOT ARISE, and was measured on the move that prompted the change rather than
+ * argued: the Power Plant sat at (-1,3) against a sign at 3, and (-2,2) and (-2,3) were both free,
+ * legal and inside. A Facility at the limit keeps six of its nine spots, and the Limits move outward
+ * as the Running Track grows (§2.1, Gap 4a), so the ground for a Modifier arrives with the district.
+ * `check` bars them from the Running Track ROW as well, which is the ground the main grows onto.
  */
 export function withinLimits(area: OfficeArea, coord: GridCoord): boolean {
   return coord.col >= area.limitsWest.col && coord.col <= area.limitsEast.col;