Fix scanner duplicating a game that was ended early

app/features/scanner/README.md

@@ -339,7 +339,10 @@ sequenceDiagram
   timeline also holds history screens to a 0.75 confidence floor (clean
   reads score 0.81+). Likewise a results screen read again with no
   match opened since (a lost-connection dialog hid it and the detector
-  re-armed) joins the last match. An event belongs to at most one match; deaths
+  re-armed) joins the last match. A no-contest results screen (the host
+  ended the game or a disconnect did early: DRAW tags on both team boxes,
+  drawn grey, and "No contest." for a score — `noContest`) discards the game
+  being gathered, so the replay of that map is its only card. An event belongs to at most one match; deaths
   reveal enemy builds (`ability-harvest.ts`), the personal results screen
   (`ScoreboardOwn`, seen within `OWN_RESULTS_WINDOW_SECONDS` of a closed
   match's scoreboard) completes the POV player's full build, and minimap

app/features/scanner/core/detectors/scoreboard/index.ts

@@ -11,6 +11,7 @@ import type { ScannerLobby } from "../../../scanner-types";
 import type { Mat } from "../../cv";
 import { type GlyphSet, scaleGlyphSet } from "../../glyphs";
 import {
+	copyRoi,
 	cropRoi,
 	frameGray,
 	frameRgb,
@@ -36,6 +37,9 @@ import {
 	gateDarkProbe,
 	MATCH_SCORE_DIGIT_HEIGHTS,
 	MATCH_SCORE_ROIS,
+	NO_CONTEST_GREY_VALUE_RANGE,
+	NO_CONTEST_INK_MIN_SATURATION,
+	NO_CONTEST_MAX_INK_SHARE,
 	nameRoi,
 	PAINT_DIGIT_HEIGHT,
 	paintRoi,
@@ -44,6 +48,7 @@ import {
 	ROW_CENTERS,
 	specialIconRoi,
 	statRoi,
+	TEAM_BOX_BAND_ROIS,
 	TEAM_DIGIT_HEIGHT,
 	TEAM_SCORE_ROIS,
 	weaponRoi,
@@ -70,6 +75,11 @@ export interface ScoreboardData {
 	stage: StageId | null;
 	/** "Score:" banner scores, [winner, loser]; a knockout's winner reports 100 (the burst hides the banner) */
 	matchScores: [number | null, number | null];
+	/**
+	 * Results screen only: the game ended before it was decided (host ended it,
+	 * early disconnect) — DRAW on both grey team boxes, "No contest." for a score
+	 */
+	noContest?: boolean;
 	/** 8 players: rows 0-3 winning team, rows 4-7 losing team */
 	players: ScoreboardPlayer[];
 	/** index into `players` of the yellow-arrow row; null when none (spectator footage) */
@@ -320,6 +330,7 @@ export function createScoreboardDetector(
 					mode: header?.mode ?? null,
 					stage: header?.stage ?? null,
 					matchScores,
+					noContest: isNoContest(rgb),
 					players,
 					povIndex,
 				},
@@ -342,3 +353,28 @@ export function createScoreboardDetector(
 		parseSteps,
 	};
 }
+
+function isNoContest(rgb: Mat): boolean {
+	return TEAM_BOX_BAND_ROIS.every((roi) => {
+		const band = copyRoi(rgb, roi);
+		const pixels = band.data as Uint8Array;
+		const channels = band.channels();
+		let ink = 0;
+		let valueSum = 0;
+		for (let i = 0; i < pixels.length; i += channels) {
+			const value = Math.max(pixels[i]!, pixels[i + 1]!, pixels[i + 2]!);
+			const spread =
+				value - Math.min(pixels[i]!, pixels[i + 1]!, pixels[i + 2]!);
+			if (value > 0 && spread >= NO_CONTEST_INK_MIN_SATURATION * value) ink++;
+			valueSum += value;
+		}
+		band.delete();
+		const count = pixels.length / channels;
+		const meanValue = valueSum / count;
+		return (
+			ink / count <= NO_CONTEST_MAX_INK_SHARE &&
+			meanValue >= NO_CONTEST_GREY_VALUE_RANGE[0] &&
+			meanValue <= NO_CONTEST_GREY_VALUE_RANGE[1]
+		);
+	});
+}

app/features/scanner/core/detectors/scoreboard/rois.ts

@@ -52,6 +52,25 @@ export const TEAM_SCORE_ROIS: readonly [Roi, Roi] = [
 	{ x: 1530, y: 684, w: 132, h: 44 },
 ];
 
+/**
+ * Team box header bands between the result tag and the total: team ink on a
+ * decided game; on a no contest (the host ended it, an early disconnect) both
+ * boxes are flat grey under DRAW tags, with no totals.
+ */
+export const TEAM_BOX_BAND_ROIS: readonly [Roi, Roi] = [
+	{ x: 1260, y: 330, w: 240, h: 34 },
+	{ x: 1260, y: 684, w: 240, h: 34 },
+];
+
+/**
+ * No-contest box band: saturated share at most this (inked boxes read ~1.0,
+ * the grey ones 0), at a mean value in the box grey's range (~103) rather than
+ * the darker panel a box still sliding in would leave.
+ */
+export const NO_CONTEST_MAX_INK_SHARE = 0.05;
+export const NO_CONTEST_INK_MIN_SATURATION = 0.35;
+export const NO_CONTEST_GREY_VALUE_RANGE: readonly [number, number] = [80, 140];
+
 /**
  * "Score:" banner sides: left from x~946, right ending x~1691 (x~1712 mid-pop); digits bounce
  * 28-39px as they land.

app/features/scanner/core/match-builder.ts

@@ -253,8 +253,10 @@ export type MatchBuildCache<E extends DetectedEvent> = WeakMap<
  * match of its own and the game being gathered stays open. A history screen
  * with its stage unread and no built match forms none. A map intro right
  * after a replay-browser entry of its stage and mode is that replay played
- * back: its gameplay joins the entry's match. Every input event ends up in at
- * most one match's `sources`.
+ * back: its gameplay joins the entry's match. A results screen of a no contest
+ * (DRAW tags: the host ended the game, an early disconnect) discards the game
+ * being gathered: it has no result, and its replay forms the real match. Every
+ * input event ends up in at most one match's `sources`.
  *
  * `unbacked` also emits, flagged, the stretches with kill reads no scoreboard,
  * minimap or played counter backed (a results screen missed, the map never
@@ -342,6 +344,12 @@ export function buildScannerMatches<E extends DetectedEvent>(
 				vote(open.stageVotes, (board!.data as ScoreboardData).stage);
 			}
 		} else if (SCOREBOARD_EVENT_TYPES.includes(event.type)) {
+			if ((event.data as ScoreboardData).noContest) {
+				// ended undecided: the game being gathered has no result to keep
+				open = null;
+				dropOrphans();
+				continue;
+			}
 			if (HISTORY_SCOREBOARD_EVENT_TYPES.includes(event.type)) {
 				lastHistoryScreen = event;
 			}

app/features/scanner/node/fixtures.ts

@@ -91,6 +91,8 @@ interface ExpectedScoreboard {
 		replayCode?: string;
 		/** the "Score:" banner game scores, [winner, loser]; KO winner = 100 */
 		matchScores?: [number | null, number | null];
+		/** Scoreboard only: the game ended before it was decided (DRAW tags, "No contest."); absent = false */
+		noContest?: boolean;
 		players?: ExpectedPlayer[];
 		/** index of the yellow POV-arrow row in `players`; null = no arrow */
 		povIndex?: number | null;

app/features/scanner/tests/fixtures/scoreboard/private-battle-clam-blitz-no-contest-draw/expected.json

@@ -0,0 +1,25 @@
+{
+	"event": "Scoreboard",
+	"data": {
+		"lobby": "PRIVATE",
+		"mode": "CB",
+		"stage": 8,
+		"stageLabel": "Inkblot Art Academy",
+		"matchScores": [null, null],
+		"noContest": true,
+		"povIndex": 1,
+		"players": [
+			{ "name": "Mini Kagu", "paint": 4, "ka": 0, "d": 0, "s": 0 },
+			{ "name": "Sendou", "weaponId": 4001, "paint": 0, "ka": 0, "d": 0, "s": 0 },
+			{ "paint": 41, "ka": 0, "d": 0, "s": 0 },
+			{ "name": "Moonluck?", "paint": 0, "ka": 0, "d": 0, "s": 0 },
+			{ "paint": 0, "ka": 0, "d": 0, "s": 0 },
+			{ "paint": 8, "ka": 0, "d": 0, "s": 0 },
+			{ "name": "lidloite", "paint": 0, "ka": 0, "d": 0, "s": 0 },
+			{ "paint": 0, "ka": null, "d": null, "s": null }
+		]
+	},
+	"options": {
+		"notes": "gacha-tournament VoD, t=4149.5 (1:09:09). The host ended the battle ~10s in (\"Mini Kagu has ended the battle.\"), so the results screen is a no contest: \"No contest.\" where the Score: banner goes and both team boxes flat grey with DRAW tags instead of team ink and VICTORY/DEFEAT, no team totals. The game was then replayed on the same map and built as a duplicate card. Row 7's stats show \"x --\" (unread by the game). Weapons other than the POV's and the decorated names are left unlabeled."
+	}
+}

app/features/scanner/tests/logic/match-builder.test.ts

@@ -119,6 +119,7 @@ function scoreboard(
 		matchScores = [100, 47] as [number | null, number | null],
 		paints = [] as (number | null)[],
 		names = NAMES,
+		noContest = false,
 	} = {},
 ): DetectedEvent {
 	const data: ScoreboardData = {
@@ -126,6 +127,7 @@ function scoreboard(
 		mode,
 		stage,
 		matchScores,
+		noContest,
 		players: weaponIds.map((weaponId, i) => ({
 			name: names[i] ?? `p${i}`,
 			weaponId,
@@ -982,6 +984,21 @@ test("a scoreless match replayed on the same map is a disconnect", () => {
 	assert.equal(skipped.get(built[1]!), undefined);
 });
 
+test("a game ended as a no contest builds no match", () => {
+	const built = buildScannerMatches([
+		mapStart(0),
+		objective(13, { time: 287, score: [100, 100] }),
+		death(14, "l1"),
+		scoreboard(35, { matchScores: [null, null], noContest: true }),
+		scoreboard(38, { matchScores: [null, null], noContest: true }),
+		mapStart(140),
+		scoreboard(440),
+	]);
+	assert.equal(built.length, 1);
+	assert.equal(built[0]!.match.startsAt, 140);
+	assert.deepEqual(built[0]!.match.matchScores, [100, 47]);
+});
+
 test("a full-length match whose score went unread is kept when the same map follows", () => {
 	const built = buildScannerMatches([
 		mapStart(0),

app/features/scanner/tests/scoreboard.test.ts

@@ -62,6 +62,10 @@ for (const fixture of fixtures) {
 			},
 		);
 
+		await t.test("noContest", fieldTestOptions(fixture, "noContest"), () => {
+			assert.equal(event.data.noContest, expected.noContest ?? false);
+		});
+
 		await t.test(
 			"header",
 			fieldTestOptions(fixture, "header", expected.mode !== undefined),

changelog/2026-10-18-scanner-no-contest.md

@@ -0,0 +1,5 @@
+---
+navItem: scanner
+type: bug
+---
+Fixed the scanner showing a game twice when the host ended it early and it was replayed, private battles ended early by participant as "No contest" are not ignored