Avoid building a full rank map for pair updates

src/commands/ResetNoteRating.ts

@@ -8,7 +8,7 @@ import type { PluginDataStore } from '../storage/PluginDataStore';
 import { ConfirmModal } from '../ui/ConfirmModal';
 import { ALL_SENTINEL, ResetNoteModal } from '../ui/ResetNoteModal';
 import {
-  computeRankMap,
+  computeRanksForAll,
   updateCohortFrontmatter,
   writeFrontmatterStatsForPlayer,
 } from '../utils/FrontmatterStats';
@@ -88,7 +88,7 @@ export async function resetNoteRating(
       def.frontmatterOverrides,
     );
 
-    const rankMap = computeRankMap(cohort);
+    const rankMap = computeRanksForAll(cohort);
 
     // Write the reset note's own stats (rating, matches, wins, rank)
     await writeFrontmatterStatsForPlayer(app, fm, cohort, file, noteId, rankMap);

src/domain/report/TemplatePlaceholders.ts

@@ -189,7 +189,9 @@ export function computePlaceholders(
     const sessionWithSigma = allWithSigma.filter(({ id }) => uniquePlayerIds.has(id));
 
     const formatStabilityList = (entries: { id: string; sigma: number }[]) =>
-      entries.map((e) => `- ${idToName(e.id, data.idToPath)} (σ ${Math.round(e.sigma)})`).join('\n');
+      entries
+        .map((e) => `- ${idToName(e.id, data.idToPath)} (σ ${Math.round(e.sigma)})`)
+        .join('\n');
 
     // Session participants only
     const byStabilitySession = sessionWithSigma.slice().sort((a, b) => a.sigma - b.sigma);

src/main.ts

@@ -22,7 +22,7 @@ import { CohortPicker } from './ui/CohortPicker';
 import { ensureBaseCohortTarget } from './utils/EnsureBaseCohort';
 import { ensureFolderCohortPath } from './utils/EnsureFolderCohort';
 import { ensureUniqueIds } from './utils/EnsureUniqueIds';
-import { computeRankMap, updateCohortFrontmatter } from './utils/FrontmatterStats';
+import { computeRanksForAll, updateCohortFrontmatter } from './utils/FrontmatterStats';
 import { debugWarn, setDebugLogging } from './utils/logger';
 
 export default class GlickoPlugin extends Plugin {
@@ -262,7 +262,7 @@ export default class GlickoPlugin extends Plugin {
     });
     if (files.length === 0) return;
 
-    const rankMap = computeRankMap(cohort);
+    const rankMap = computeRanksForAll(cohort);
 
     updateCohortFrontmatter(
       this.app,

src/settings/SettingsTab.ts

@@ -9,7 +9,7 @@ import { ConfirmModal } from '../ui/ConfirmModal';
 import { FolderSelectModal } from '../ui/FolderPicker';
 import { FM_PROP_KEYS, renderStandardFmPropertyRow } from '../ui/FrontmatterPropertyRow';
 import {
-  computeRankMap,
+  computeRanksForAll,
   previewCohortFrontmatterPropertyUpdates,
   updateCohortFrontmatter,
 } from '../utils/FrontmatterStats';
@@ -562,7 +562,7 @@ export default class GlickoSettingsTab extends PluginSettingTab {
       const map = new Map<string, number>();
       if (!cohort) return map;
       if (key === 'rank') {
-        const rankMap = computeRankMap(cohort);
+        const rankMap = computeRanksForAll(cohort);
         for (const [id, rank] of rankMap) map.set(id, rank);
       } else if (key === 'rating') {
         for (const [id, p] of Object.entries(cohort.players)) map.set(id, Math.round(p.rating));

src/storage/PluginDataStore.ts

@@ -214,7 +214,11 @@ export class PluginDataStore {
       ts: now,
     };
 
-    // Inflate sigma for staleness (Glicko-1 RD inflation)
+    // Inflate sigma for staleness (Glicko-1 RD inflation).
+    // Cap is intentionally stabilityThreshold, not DEFAULT_SIGMA: notes don't
+    // "lose skill" like human players, so we only allow modest RD inflation to
+    // accommodate preference drift. This also prevents the stability progress
+    // bar from regressing after long gaps between sessions.
     const cap = this.settings.stabilityThreshold ?? 150;
     const preSigmaA = inflateSigma(a.sigma ?? DEFAULT_SIGMA, now - (a.lastMatchAt ?? now), cap);
     const preSigmaB = inflateSigma(b.sigma ?? DEFAULT_SIGMA, now - (b.lastMatchAt ?? now), cap);

src/utils/FrontmatterStats.ts

@@ -17,7 +17,7 @@ function anyEnabled(fm: FrontmatterPropertiesSettings): boolean {
 }
 
 // Standard competition ranking ("1224" style)
-export function computeRankMap(cohort: CohortData): Map<string, number> {
+export function computeRanksForAll(cohort: CohortData): Map<string, number> {
   const entries = Object.entries(cohort.players);
   entries.sort((a, b) => b[1].rating - a[1].rating);
 
@@ -38,6 +38,33 @@ export function computeRankMap(cohort: CohortData): Map<string, number> {
   return map;
 }
 
+// Compute ranks for a subset of players by counting how many players
+// have a strictly higher rating (standard competition ranking)
+function computeRanksForSubset(cohort: CohortData, playerIds: string[]): Map<string, number> {
+  const targets = playerIds
+    .map((id) => ({ id, rating: cohort.players[id]?.rating }))
+    .filter((t): t is { id: string; rating: number } => t.rating !== undefined);
+
+  if (targets.length === 0) return new Map();
+
+  // For each player in the cohort, check if their rating exceeds
+  // any target's rating and increment that target's rank counter
+  const higherCounts = new Map<string, number>(targets.map((t) => [t.id, 0]));
+  for (const player of Object.values(cohort.players)) {
+    for (const t of targets) {
+      if (player.rating > t.rating) {
+        higherCounts.set(t.id, higherCounts.get(t.id)! + 1);
+      }
+    }
+  }
+
+  const rankMap = new Map<string, number>();
+  for (const [id, count] of higherCounts) {
+    rankMap.set(id, count + 1);
+  }
+  return rankMap;
+}
+
 function buildProps(fm: FrontmatterPropertiesSettings, stats: PlayerStats): Record<string, number> {
   const out: Record<string, number> = {};
 
@@ -78,7 +105,8 @@ export async function writeFrontmatterStatsForPair(
   if (!cohort) return;
   if (!anyEnabled(fm)) return;
 
-  const rankMap = computeRankMap(cohort);
+  const ids = [aId, bId].filter((id): id is string => !!id);
+  const rankMap = computeRanksForSubset(cohort, ids);
   const tasks: Promise<void>[] = [];
 
   if (aFile && aId) {
@@ -258,7 +286,7 @@ export async function updateCohortRanksInFrontmatter(
   newPropName: string,
 ): Promise<{ updated: number }> {
   if (!cohort) return { updated: 0 };
-  const rankMap = computeRankMap(cohort);
+  const rankMap = computeRanksForAll(cohort);
   return updateCohortFrontmatterProperties(app, files, rankMap, newPropName);
 }
 
@@ -268,12 +296,12 @@ export async function writeFrontmatterStatsForPlayer(
   cohort: CohortData,
   file: TFile,
   playerId: string,
-  precomputedRankMap?: Map<string, number>,
+  precomputedRankMap: Map<string, number>,
 ): Promise<void> {
   if (!anyEnabled(fm)) return;
   const p = cohort.players[playerId];
   if (!p) return;
-  const rankMap = precomputedRankMap ?? computeRankMap(cohort);
+  const rankMap = precomputedRankMap;
   const props = buildProps(fm, {
     rating: p.rating,
     matches: p.matches,