diff --git a/convex/_model/tournamentResults/_helpers/aggregateTournamentData.ts b/convex/_model/tournamentResults/_helpers/aggregateTournamentData.ts
index 03fab27d..a9919edb 100644
--- a/convex/_model/tournamentResults/_helpers/aggregateTournamentData.ts
+++ b/convex/_model/tournamentResults/_helpers/aggregateTournamentData.ts
@@ -116,6 +116,7 @@ export const aggregateTournamentData = async (
   }
 
   // ---- 3. Convert stats to ranking factors for players and competitors ----
+  const roundsPlayed = round + 1; // Add 1 to get length rather than index
   return {
     registrations: Object.entries(registrationStats).map(([key, { results }]) => {
       const id = key as Id<'tournamentRegistrations'>;
@@ -123,7 +124,7 @@ export const aggregateTournamentData = async (
         id,
         gamesPlayed: results.length,
         opponentIds: Array.from(new Set(results.map((s) => s.opponentId))).filter((id) => id !== null),
-        rankingFactors: computeRankingFactors(id, registrationStats, defaultBaseStats, round),
+        rankingFactors: computeRankingFactors(id, registrationStats, defaultBaseStats, roundsPlayed),
         rank: -1,
       };
     }),
@@ -139,7 +140,7 @@ export const aggregateTournamentData = async (
         opponentIds: Array.from(new Set(results.map((s) => s.opponentId))).filter((id) => id !== null),
         playedTables: Array.from(playedTables),
         byeRounds: Array.from(byeRounds),
-        rankingFactors: computeRankingFactors(id, competitorStats, defaultBaseStats, round),
+        rankingFactors: computeRankingFactors(id, competitorStats, defaultBaseStats, roundsPlayed),
         rank: -1,
       };
     }),
diff --git a/convex/_model/tournaments/triggers.ts b/convex/_model/tournaments/triggers.ts
index e1c9e7e3..ef92b529 100644
--- a/convex/_model/tournaments/triggers.ts
+++ b/convex/_model/tournaments/triggers.ts
@@ -1,6 +1,43 @@
+import isEqual from 'fast-deep-equal/es6';
+
 import { MutationCtx } from '../../_generated/server';
 import { TriggerChange } from '../common/types';
 import { refreshLeagueRankings as refreshLeagueRankingsHandler } from '../leagues';
+import { refreshTournamentResult } from '../tournamentResults';
+
+/**
+ * Trigger refresh of tournament results when ranking factors change.
+ * 
+ * Only refreshes when fields that affect ranking change:
+ * - rankingFactors
+ */
+export const refreshTournamentResults = async (
+  ctx: MutationCtx,
+  change: TriggerChange<'tournaments'>,
+): Promise<void> => {
+  const { newDoc, oldDoc } = change;
+
+  if (!newDoc || !oldDoc) {
+    return;
+  }
+
+  if (newDoc.status === 'draft' || newDoc.status === 'published') {
+    return;
+  }
+
+  // For updates, skip if no ranking-relevant fields changed:
+  if (isEqual(newDoc.rankingFactors, oldDoc.rankingFactors)) {
+    return;
+  }
+
+  const tournamentResults = await ctx.db.query('tournamentResults')
+    .withIndex('by_tournament_round', (q) => q.eq('tournamentId', change.id))
+    .collect();
+
+  for (const tournamentResult of tournamentResults) {
+    await refreshTournamentResult(ctx, tournamentResult);
+  }
+};
 
 /**
  * Trigger refresh of league rankings when a tournament is archived.
diff --git a/convex/functions.ts b/convex/functions.ts
index c0c0203f..5b69fc04 100644
--- a/convex/functions.ts
+++ b/convex/functions.ts
@@ -78,3 +78,4 @@ triggers.register('tournamentCompetitors', tournamentCompetitorTriggers.refreshT
 triggers.register('tournamentRegistrations', tournamentRegistrationTriggers.refreshTournamentResults);
 triggers.register('tournamentResults', tournamentResultTriggers.refreshLeagueRankings);
 triggers.register('tournaments', tournamentTriggers.refreshLeagueRankings);
+triggers.register('tournaments', tournamentTriggers.refreshTournamentResults);
diff --git a/convex/migrations.ts b/convex/migrations.ts
index 0e19046a..48314e6f 100644
--- a/convex/migrations.ts
+++ b/convex/migrations.ts
@@ -50,17 +50,14 @@ export const fixMissingListData = migrations.define({
   },
 });
 
-export const migrateTournamentResults = migrations.define({
+export const refreshTournamentResults = migrations.define({
   table: 'tournaments',
   migrateOne: async (ctx, doc) => {
-    if (doc.status === 'archived') {
-      const rounds = doc.lastRound !== undefined ? doc.lastRound + 1 : doc.roundCount;
-      for (let i = 0; i < rounds; i++) {
-        await refreshTournamentResult(ctx, {
-          tournamentId: doc._id,
-          round: i,
-        });
-      }
+    const tournamentResults = await ctx.db.query('tournamentResults')
+      .withIndex('by_tournament_round', (q) => q.eq('tournamentId', doc._id))
+      .collect();
+    for (const result of tournamentResults) {
+      await refreshTournamentResult(ctx, result);
     }
   },
 });