diff --git a/UPDATES.md b/UPDATES.md
index 851a658..3388c95 100644
--- a/UPDATES.md
+++ b/UPDATES.md
@@ -1,9 +1,13 @@
 ---
-updatedAt: 2026-09-10T10:52:51+09:00
+updatedAt: 2026-09-10T14:39:25+09:00
 ---
 
 ## 2026년 9월 10일
 
+### 시간별 최고점 유지 확률
+
+`NEW` 배치 분석의 시간별 점수 그래프에 커서를 올리면 해당 시각까지 최고점을 유지할 확률을 함께 표시합니다. 모든 노트 PERFECT와 액티브 발동 확률을 기준으로 계산하며, 액티브 미발동 토글 시 현재 설정의 최고점 기준으로 갱신됩니다.
+
 ### 액티브 점수 영향력 표시
 
 `NEW` 배치 분석에서 현재 설정의 최고점에 미치는 영향이 큰 액티브를 진한 색과 굵은 테두리로 강조합니다. 구간에 마우스를 올리면 토글 시 점수 변화를 확인할 수 있으며, 미발동 구간은 복원 시 영향력을 표시합니다.
diff --git a/src/lib/components/ScoreTimelineChart.svelte b/src/lib/components/ScoreTimelineChart.svelte
index 2497414..c1fbeda 100644
--- a/src/lib/components/ScoreTimelineChart.svelte
+++ b/src/lib/components/ScoreTimelineChart.svelte
@@ -2,6 +2,7 @@
   import type { NoteScorePoint } from '$lib/engine/index.ts';
 
   export let notes: readonly NoteScorePoint[];
+  export let maximumScoreProbabilities: readonly number[] = [];
   export let durationSeconds: number;
   export let minimumWidth = 720;
   export let timeTicks: readonly number[] = [];
@@ -10,6 +11,7 @@
     timeSeconds: number;
     averageScore: number;
     maximumScore: number;
+    maximumProbability?: number;
   };
 
   const HEIGHT = 220;
@@ -25,7 +27,7 @@
 
   $: viewWidth = Math.max(320, chartWidth);
   $: plotWidth = viewWidth - LEFT - RIGHT;
-  $: points = buildPoints(notes);
+  $: points = buildPoints(notes, maximumScoreProbabilities);
   $: finalMaximumScore = Math.max(1, points.at(-1)?.maximumScore ?? 0);
   $: chartMaximumScore = Math.max(500_000, Math.ceil(finalMaximumScore / 500_000) * 500_000);
   $: averagePath = linePath(points, 'averageScore', durationSeconds, chartMaximumScore, viewWidth);
@@ -41,14 +43,14 @@
     tooltipPercent = 0;
   }
 
-  function buildPoints(source: readonly NoteScorePoint[]): ScorePoint[] {
+  function buildPoints(source: readonly NoteScorePoint[], probabilities: readonly number[]): ScorePoint[] {
     let averageScore = 0;
     let maximumScore = 0;
-    const result: ScorePoint[] = [{ timeSeconds: 0, averageScore: 0, maximumScore: 0 }];
-    for (const note of source) {
+    const result: ScorePoint[] = [{ timeSeconds: 0, averageScore: 0, maximumScore: 0, maximumProbability: 1 }];
+    for (const [index, note] of source.entries()) {
       averageScore += note.expectedScore;
       maximumScore += note.theoreticalMaxScore;
-      result.push({ timeSeconds: note.timeSeconds, averageScore, maximumScore });
+      result.push({ timeSeconds: note.timeSeconds, averageScore, maximumScore, maximumProbability: probabilities[index] });
     }
     return result;
   }
@@ -114,6 +116,12 @@
     return Math.round(score).toLocaleString('ko-KR');
   }
 
+  function formatProbability(probability: number | undefined): string {
+    if (probability === undefined) return '—';
+    if (probability > 0 && probability < 0.000001) return '<0.0001%';
+    return `${(probability * 100).toLocaleString('ko-KR', { maximumFractionDigits: probability < 0.0001 ? 4 : 2 })}%`;
+  }
+
   function formatAxisScore(score: number): string {
     return score === 0 ? '0' : `${Math.round(score / 10_000).toLocaleString('ko-KR')}만`;
   }
@@ -147,7 +155,7 @@
     aria-valuemin="0"
     aria-valuemax={Math.ceil(durationSeconds)}
     aria-valuenow={Math.round(hoverTime ?? 0)}
-    aria-valuetext={hoveredPoint && hoverTime !== null ? `${formatTime(hoverTime)}, 평균 점수 ${formatScore(hoveredPoint.averageScore)}, 최고 점수 ${formatScore(hoveredPoint.maximumScore)}` : '방향키로 시각을 선택하세요'}
+    aria-valuetext={hoveredPoint && hoverTime !== null ? `${formatTime(hoverTime)}, 평균 점수 ${formatScore(hoveredPoint.averageScore)}, 최고 점수 ${formatScore(hoveredPoint.maximumScore)}, 이 시간까지 최고점 유지 확률 ${formatProbability(hoveredPoint.maximumProbability)}` : '방향키로 시각을 선택하세요'}
     tabindex="0"
     on:pointermove={onPointerMove}
     on:pointerleave={() => hoverTime = null}
@@ -176,10 +184,11 @@
     </svg>
 
     {#if hoveredPoint && hoverTime !== null}
-      <div class:align-right={tooltipPercent > 68} class="tooltip" style={`left: ${tooltipPercent}%;`} role="status">
+      <div class:align-right={tooltipPercent > 50} class="tooltip" style={`left: ${tooltipPercent}%;`} role="status">
         <strong>{formatTime(hoverTime)}</strong>
         <span><i class="average"></i>평균 점수 <b>{formatScore(hoveredPoint.averageScore)}</b></span>
         <span><i class="maximum"></i>최고 점수 <b>{formatScore(hoveredPoint.maximumScore)}</b></span>
+        <span>이 시간까지 최고점 유지 확률 <b>{formatProbability(hoveredPoint.maximumProbability)}</b></span>
       </div>
     {/if}
   </div>
diff --git a/src/lib/engine/score-probability.test.ts b/src/lib/engine/score-probability.test.ts
index 24d6b80..2dcc56a 100644
--- a/src/lib/engine/score-probability.test.ts
+++ b/src/lib/engine/score-probability.test.ts
@@ -1,6 +1,7 @@
 import assert from 'node:assert/strict';
 import test from 'node:test';
 import { estimateScoreAchievementProbabilities } from './index.ts';
+import { calculateMaximumScoreProbabilityTimeline } from './score-probability.ts';
 import type { ExactSongChart, OptimizerCard } from './types.ts';
 
 function card(
@@ -104,3 +105,32 @@ test('확정 발동이면 모든 달성 확률이 100%다', () => {
     samples: 1_000
   });
 });
+
+test('시간별 최고점 확률은 첫 영향 노트에서 감소하고 같은 발동을 중복 계산하지 않는다', () => {
+  const cards = [card('main', 100, 50, 0.9), card('weak', 20, 10)];
+  const source = chart([0.5, 1.1, 1.5, 1.95, 2.1, 2.1]);
+  const options = { perfectNoteScore: 100, sampleCount: 1 };
+  const probabilities = calculateMaximumScoreProbabilityTimeline(cards, {}, source, options);
+  // The weak skill alone raises the maximum at 1.95 seconds.
+  assert.deepEqual(probabilities, [1, 0.5, 0.5, 0.05, 0.025, 0.025]);
+  assert.equal(probabilities.at(-1), estimateScoreAchievementProbabilities(cards, {}, source, options).maximum);
+  assert.deepEqual(calculateMaximumScoreProbabilityTimeline(cards, {}, chart([]), options), []);
+});
+
+test('시간별 확률은 겹친 동률 액티브와 이후 필수 발동 사이의 의존성을 반영한다', () => {
+  const cards = [card('long', 100, 50, 0.9), card('short', 100, 50, 0.3)];
+  assert.deepEqual(calculateMaximumScoreProbabilityTimeline(cards, {}, chart([1.1, 1.5, 2.1]), {
+    perfectNoteScore: 100
+  }), [0.75, 0.5, 0.375]);
+});
+
+test('미발동 토글 시 현재 최고점 기준으로 확률을 계산하고 반올림으로 점수가 같으면 실패를 허용한다', () => {
+  const cards = [card('strong', 100, 50), card('weak', 20, 10)];
+  assert.deepEqual(calculateMaximumScoreProbabilityTimeline(cards, {}, chart([1.1, 2.1]), {
+    perfectNoteScore: 100,
+    excludedActiveWindows: [{ cardId: 'strong', startSeconds: 1 }]
+  }), [0.1, 0.05]);
+  const options = { perfectNoteScore: 0.1, sampleCount: 1 };
+  assert.deepEqual(calculateMaximumScoreProbabilityTimeline(cards, {}, chart([1.1]), options), [1]);
+  assert.equal(estimateScoreAchievementProbabilities(cards, {}, chart([1.1]), options).maximum, 1);
+});
diff --git a/src/lib/engine/score-probability.ts b/src/lib/engine/score-probability.ts
index 444a1d3..61a54f8 100644
--- a/src/lib/engine/score-probability.ts
+++ b/src/lib/engine/score-probability.ts
@@ -62,7 +62,8 @@ function prepareModel(
   cards: readonly OptimizerCard[],
   reductions: Readonly<Record<string, CooldownReduction>>,
   chart: ExactSongChart,
-  options: ExactScoreOptions
+  options: ExactScoreOptions,
+  onNote?: (probability: number) => void
 ): PreparedProbabilityModel {
   const attempts: Attempt[] = [];
   const attemptIndexes = new Map<string, number>();
@@ -70,6 +71,8 @@ function prepareModel(
   const grouped = new Map<string, { candidates: NoteCandidate[]; scores: number[] }>();
   const clauses: number[][] = [];
   let maximumScore = 0;
+  let prefixProbability = 1;
+  let prefixClauses: number[][] = [];
 
   scoreNotes(chart).forEach((note, noteIndex) => {
     const candidates: NoteCandidate[] = [];
@@ -80,6 +83,8 @@ function prepareModel(
       const attemptNumber = Math.floor((note.timeSeconds + 1e-9) / interval);
       if (attemptNumber <= 0) return;
       const activationTime = attemptNumber * interval;
+      if (options.excludedActiveWindows?.some((window) =>
+        window.cardId === card.id && Math.abs(window.startSeconds - activationTime) < 1e-9)) return;
       if (note.timeSeconds >= activationTime + card.active.durationSeconds) return;
       const key = `${card.id}:${attemptNumber}`;
       let attemptIndex = attemptIndexes.get(key);
@@ -110,11 +115,18 @@ function prepareModel(
     ];
     maximumScore += scores[0];
 
-    if (candidates.length > 0) {
-      clauses.push(candidates
+    // No activation is required when rounding gives the baseline the same score.
+    if (scores[0] > scores[scores.length - 1]) {
+      const clause = candidates
         .filter((_, index) => scores[index] === scores[0])
-        .map((candidate) => candidate.attemptIndex));
+        .map((candidate) => candidate.attemptIndex);
+      clauses.push(clause);
+      if (onNote && !prefixClauses.some((existing) => existing.every((variable) => clause.includes(variable)))) {
+        prefixClauses = simplifyClauses([...prefixClauses, clause]);
+        prefixProbability = exactClauseProbability(prefixClauses, attempts);
+      }
     }
+    onNote?.(prefixProbability);
 
     const signature = candidates.map((candidate) => `${candidate.attemptIndex}:${candidate.boost.toPrecision(15)}`).join('|');
     const existing = grouped.get(signature);
@@ -130,6 +142,18 @@ function prepareModel(
   };
 }
 
+/** Exact cumulative maximum-score probability after each chart note, in note order. */
+export function calculateMaximumScoreProbabilityTimeline(
+  cards: readonly OptimizerCard[],
+  reductions: Readonly<Record<string, CooldownReduction>>,
+  chart: ExactSongChart,
+  options: ExactScoreOptions
+): number[] {
+  const probabilities: number[] = [];
+  prepareModel(cards, reductions, chart, options, (probability) => probabilities.push(probability));
+  return probabilities;
+}
+
 function simplifyClauses(clauses: readonly (readonly number[])[]): number[][] {
   const unique = new Map<string, number[]>();
   for (const clause of clauses) {
diff --git a/src/routes/analysis/+page.svelte b/src/routes/analysis/+page.svelte
index c9724a1..cbf25d4 100644
--- a/src/routes/analysis/+page.svelte
+++ b/src/routes/analysis/+page.svelte
@@ -18,6 +18,7 @@
   import { releasedSongCharts } from '$lib/data/song-release.ts';
   import PresetManager from '$lib/components/PresetManager.svelte';
   import ScoreTimelineChart from '$lib/components/ScoreTimelineChart.svelte';
+  import { calculateMaximumScoreProbabilityTimeline } from '$lib/engine/score-probability.ts';
   import SongPicker from '$lib/components/SongPicker.svelte';
   import { buildExactSkillWindows, calculateBoardEffects, calculateExactScore, calculateUnitPower, countOptimizationCandidates, finalNoteScore, memoryParameterPermil, optimizeBoardConnectionCards, optimizeExactOrderAndCooldowns, perfectNoteScoreFromPower, toOptimizerCard } from '$lib/engine/index.ts';
   import type { ExactScoreOptions, OptimizerCard, CooldownReduction, EffectiveSkillWindow, ExactOptimizationResult, ExactSongChart, OptimizableConnectionCard, OptimizationProgress, ScoreAchievementProbabilities, SkillWindow } from '$lib/engine/index.ts';
@@ -134,6 +135,13 @@
     excludedActiveWindows = [];
   }
   $: displayedResult = simulatedResult ?? result;
+  $: maximumScoreProbabilities = result && simulationContext
+    ? calculateMaximumScoreProbabilityTimeline(
+      result.order.map((id) => simulationContext!.cards.find((card) => card.id === id)!),
+      result.cooldownReductions, simulationContext.chart,
+      { ...simulationContext.options, excludedActiveWindows }
+    )
+    : [];
   $: activeImpacts = result && simulationContext && mode === 'analysis'
     ? calculateActiveImpacts(
       result.order.map((id) => simulationContext!.cards.find((card) => card.id === id)!),
@@ -1215,7 +1223,7 @@
         {/if}
         <div class="timeline-scroll" role="region" aria-label="스킬 발동 시간대 그래프">
           <div class="timeline-canvas" style={`width: ${timelineWidth + 156}px;`}>
-            <ScoreTimelineChart notes={displayedResult!.notes} durationSeconds={timelineDuration} minimumWidth={timelineWidth} timeTicks={timelineTicks} />
+            <ScoreTimelineChart notes={displayedResult!.notes} {maximumScoreProbabilities} durationSeconds={timelineDuration} minimumWidth={timelineWidth} timeTicks={timelineTicks} />
             {#each result.order as cardId, slot}
               <div class="timeline-row member-row">
                 <strong class="lane-label"><small style={`--member-color: ${memberColor(cardId)};`}>{slot + 1}</small>{resultCardName(cardId)}</strong>