diff --git a/src/components/admin-match-analysis.tsx b/src/components/admin-match-analysis.tsx
index edb7d1f..411c85c 100644
--- a/src/components/admin-match-analysis.tsx
+++ b/src/components/admin-match-analysis.tsx
@@ -3,6 +3,7 @@
 import Link from "next/link";
 import { useMemo } from "react";
 import { ClickableUserId } from "@/components/clickable-user-id";
+import { AnalysisMatchAlertBox } from "@/components/analysis-match-alert-box";
 import { MatchAnalysisEmoteChart } from "@/components/match-analysis-emote-chart";
 import { MatchAnalysisForceChart } from "@/components/match-analysis-force-chart";
 import { buildDashboardHref } from "@/lib/dashboard-search-url";
@@ -269,41 +270,19 @@ export function AdminMatchAnalysis({
         </span>
       </div>
 
-      {analysis.mirrorExceptionDisconnectMatchIds.length > 0 ? (
-        <div
-          className="rounded-lg border border-red-300 bg-red-50 px-4 py-3 text-sm text-red-950 dark:border-red-800 dark:bg-red-950/50 dark:text-red-100"
-          role="alert"
-        >
-          <p className="font-medium">
-            Mirror exception disconnect (
-            {analysis.mirrorExceptionDisconnectMatchIds.length.toLocaleString(
-              "en-US",
-            )}{" "}
-            {analysis.mirrorExceptionDisconnectMatchIds.length === 1
-              ? "match"
-              : "matches"}
-            )
-          </p>
-          <p className="mt-1 text-red-800 dark:text-red-200/90">
+      <AnalysisMatchAlertBox
+        category="mirror"
+        matchIds={analysis.mirrorExceptionDisconnectMatchIds}
+        title="Mirror exception disconnect"
+        description={
+          <>
             These matches include a{" "}
             <span className="font-mono">[Mirror/Error]</span> line where a
             player was disconnected because handling a command caused an
             exception.
-          </p>
-          <ul className="mt-3 flex flex-wrap gap-2">
-            {analysis.mirrorExceptionDisconnectMatchIds.map((matchId) => (
-              <li key={matchId}>
-                <Link
-                  href={`/match-logs/${matchId}`}
-                  className="inline-flex items-center rounded-md border border-red-400/80 bg-white px-2.5 py-1 font-mono text-xs font-medium text-red-900 shadow-sm hover:bg-red-100 dark:border-red-700 dark:bg-red-950/80 dark:text-red-50 dark:hover:bg-red-900/80"
-                >
-                  Match {matchId}
-                </Link>
-              </li>
-            ))}
-          </ul>
-        </div>
-      ) : null}
+          </>
+        }
+      />
 
       <div className="grid gap-4 lg:grid-cols-3">
         <StatBlock
@@ -402,32 +381,12 @@ export function AdminMatchAnalysis({
           </div>
 
           {analysis.notEndedMatchIds.length > 0 ? (
-            <div
-              className="rounded-lg border border-amber-300 bg-amber-50 px-4 py-3 text-sm text-amber-950 dark:border-amber-800 dark:bg-amber-950/40 dark:text-amber-100"
-              role="status"
-            >
-              <p className="font-medium">
-                Not ended (
-                {analysis.notEndedMatchIds.length.toLocaleString("en-US")}{" "}
-                {analysis.notEndedMatchIds.length === 1 ? "match" : "matches"})
-              </p>
-              <p className="mt-1 text-amber-900/90 dark:text-amber-200/90">
-                Log file present but no winner PATCH line — the match did not
-                finish normally.
-              </p>
-              <ul className="mt-3 flex flex-wrap gap-2">
-                {analysis.notEndedMatchIds.map((matchId) => (
-                  <li key={matchId}>
-                    <Link
-                      href={`/match-logs/${matchId}`}
-                      className="inline-flex items-center rounded-md border border-amber-400/80 bg-white px-2.5 py-1 font-mono text-xs font-medium text-amber-950 shadow-sm hover:bg-amber-100 dark:border-amber-700 dark:bg-amber-950/80 dark:text-amber-50 dark:hover:bg-amber-900/80"
-                    >
-                      Match {matchId}
-                    </Link>
-                  </li>
-                ))}
-              </ul>
-            </div>
+            <AnalysisMatchAlertBox
+              category="notEnded"
+              matchIds={analysis.notEndedMatchIds}
+              title="Not ended"
+              description="Log file present but no winner PATCH line — the match did not finish normally."
+            />
           ) : (
             <p className="text-sm text-zinc-600 dark:text-zinc-400">
               Every match with a log file includes a winner PATCH line.
diff --git a/src/components/analysis-match-alert-box.tsx b/src/components/analysis-match-alert-box.tsx
new file mode 100644
index 0000000..254abad
--- /dev/null
+++ b/src/components/analysis-match-alert-box.tsx
@@ -0,0 +1,178 @@
+"use client";
+
+import Link from "next/link";
+import {
+  useCallback,
+  useEffect,
+  useMemo,
+  useState,
+  type MouseEvent,
+  type ReactNode,
+} from "react";
+import {
+  EMPTY_HIDDEN_MIRROR,
+  EMPTY_HIDDEN_NOT_ENDED,
+  getHiddenAnalysisMatchIds,
+  hideAnalysisMatchIds,
+  subscribeAnalysisHiddenAlerts,
+  type AnalysisAlertCategory,
+} from "@/lib/analysis-alert-hide-cookies";
+
+function CloseIcon({ className }: { className?: string }) {
+  return (
+    <svg
+      viewBox="0 0 16 16"
+      fill="none"
+      stroke="currentColor"
+      strokeWidth="2"
+      strokeLinecap="round"
+      aria-hidden
+      className={className ?? "h-3.5 w-3.5"}
+    >
+      <path d="M4 4l8 8M12 4l-8 8" />
+    </svg>
+  );
+}
+
+const STYLES: Record<
+  AnalysisAlertCategory,
+  {
+    box: string;
+    body: string;
+    chip: string;
+    dismiss: string;
+    headerDismiss: string;
+  }
+> = {
+  mirror: {
+    box: "rounded-lg border border-red-300 bg-red-50 px-4 py-3 text-sm text-red-950 dark:border-red-800 dark:bg-red-950/50 dark:text-red-100",
+    body: "text-red-800 dark:text-red-200/90",
+    chip: "inline-flex items-center gap-0.5 overflow-hidden rounded-md border border-red-400/80 bg-white shadow-sm dark:border-red-700 dark:bg-red-950/80",
+    dismiss:
+      "shrink-0 p-1 text-red-700 hover:bg-red-100 dark:text-red-200 dark:hover:bg-red-900/80",
+    headerDismiss:
+      "shrink-0 rounded-md p-1.5 text-red-800 hover:bg-red-100 dark:text-red-100 dark:hover:bg-red-900/80",
+  },
+  notEnded: {
+    box: "rounded-lg border border-amber-300 bg-amber-50 px-4 py-3 text-sm text-amber-950 dark:border-amber-800 dark:bg-amber-950/40 dark:text-amber-100",
+    body: "text-amber-900/90 dark:text-amber-200/90",
+    chip: "inline-flex items-center gap-0.5 overflow-hidden rounded-md border border-amber-400/80 bg-white shadow-sm dark:border-amber-700 dark:bg-amber-950/80",
+    dismiss:
+      "shrink-0 p-1 text-amber-800 hover:bg-amber-100 dark:text-amber-100 dark:hover:bg-amber-900/80",
+    headerDismiss:
+      "shrink-0 rounded-md p-1.5 text-amber-900 hover:bg-amber-100 dark:text-amber-50 dark:hover:bg-amber-900/80",
+  },
+};
+
+function emptyHiddenFor(category: AnalysisAlertCategory): number[] {
+  return category === "mirror" ? EMPTY_HIDDEN_MIRROR : EMPTY_HIDDEN_NOT_ENDED;
+}
+
+function useHiddenMatchIds(category: AnalysisAlertCategory): number[] {
+  const [hiddenIds, setHiddenIds] = useState<number[]>(() =>
+    emptyHiddenFor(category),
+  );
+
+  useEffect(() => {
+    setHiddenIds(getHiddenAnalysisMatchIds(category));
+    return subscribeAnalysisHiddenAlerts(() => {
+      setHiddenIds(getHiddenAnalysisMatchIds(category));
+    });
+  }, [category]);
+
+  return hiddenIds;
+}
+
+type Props = {
+  category: AnalysisAlertCategory;
+  matchIds: number[];
+  title: string;
+  description: ReactNode;
+};
+
+export function AnalysisMatchAlertBox({
+  category,
+  matchIds,
+  title,
+  description,
+}: Props) {
+  const hiddenIds = useHiddenMatchIds(category);
+  const hiddenSet = useMemo(() => new Set(hiddenIds), [hiddenIds]);
+
+  const visibleIds = useMemo(
+    () => matchIds.filter((id) => !hiddenSet.has(id)),
+    [matchIds, hiddenSet],
+  );
+
+  const hideOne = useCallback(
+    (e: MouseEvent<HTMLButtonElement>, matchId: number) => {
+      e.preventDefault();
+      e.stopPropagation();
+      hideAnalysisMatchIds(category, [matchId]);
+    },
+    [category],
+  );
+
+  const hideAll = useCallback(
+    (e: MouseEvent<HTMLButtonElement>) => {
+      e.preventDefault();
+      e.stopPropagation();
+      hideAnalysisMatchIds(category, visibleIds);
+    },
+    [category, visibleIds],
+  );
+
+  if (matchIds.length === 0 || visibleIds.length === 0) return null;
+
+  const s = STYLES[category];
+
+  return (
+    <div className={s.box} role="alert">
+      <div className="flex items-start justify-between gap-3">
+        <div className="min-w-0 flex-1">
+          <p className="font-medium">
+            {title} ({visibleIds.length.toLocaleString("en-US")}{" "}
+            {visibleIds.length === 1 ? "match" : "matches"})
+          </p>
+          <p className={`mt-1 ${s.body}`}>{description}</p>
+        </div>
+        <button
+          type="button"
+          onClick={hideAll}
+          className={s.headerDismiss}
+          aria-label="Hide all matches in this list"
+          title="Hide all"
+        >
+          <CloseIcon className="h-4 w-4" />
+        </button>
+      </div>
+      <ul className="mt-3 flex flex-wrap gap-2">
+        {visibleIds.map((matchId) => (
+          <li key={matchId}>
+            <span className={s.chip}>
+              <Link
+                href={`/match-logs/${matchId}`}
+                className={`px-2.5 py-1 font-mono text-xs font-medium ${
+                  category === "mirror"
+                    ? "text-red-900 dark:text-red-50"
+                    : "text-amber-950 dark:text-amber-50"
+                }`}
+              >
+                Match {matchId}
+              </Link>
+              <button
+                type="button"
+                onClick={(e) => hideOne(e, matchId)}
+                className={s.dismiss}
+                aria-label={`Hide match ${matchId}`}
+                title="Hide"
+              >
+                <CloseIcon />
+              </button>
+            </span>
+          </li>
+        ))}
+      </ul>
+    </div>
+  );
+}
diff --git a/src/lib/analysis-alert-hide-cookies.ts b/src/lib/analysis-alert-hide-cookies.ts
new file mode 100644
index 0000000..dbbd8a8
--- /dev/null
+++ b/src/lib/analysis-alert-hide-cookies.ts
@@ -0,0 +1,129 @@
+/** Client-side cookie storing per-admin dismissed analysis alert match ids. */
+export const ANALYSIS_HIDDEN_ALERTS_COOKIE = "kk_analysis_hidden_alerts";
+
+export type AnalysisAlertCategory = "mirror" | "notEnded";
+
+type StoredHiddenAlerts = {
+  mirror: number[];
+  notEnded: number[];
+};
+
+const EMPTY_MIRROR: number[] = [];
+const EMPTY_NOT_ENDED: number[] = [];
+
+const MAX_IDS_PER_CATEGORY = 400;
+
+const COOKIE_MAX_AGE_SEC = 60 * 60 * 24 * 365;
+
+export const ANALYSIS_HIDDEN_ALERTS_EVENT = "kk-analysis-hidden-alerts-change";
+
+/** Stable empty snapshots for useSyncExternalStore / initial state. */
+export const EMPTY_HIDDEN_MIRROR = EMPTY_MIRROR;
+export const EMPTY_HIDDEN_NOT_ENDED = EMPTY_NOT_ENDED;
+
+let storeCache: {
+  cookieValue: string;
+  mirror: number[];
+  notEnded: number[];
+} | null = null;
+
+function notifyHiddenAlertsChanged(): void {
+  if (typeof window !== "undefined") {
+    window.dispatchEvent(new Event(ANALYSIS_HIDDEN_ALERTS_EVENT));
+  }
+}
+
+export function subscribeAnalysisHiddenAlerts(
+  onStoreChange: () => void,
+): () => void {
+  if (typeof window === "undefined") return () => {};
+  window.addEventListener(ANALYSIS_HIDDEN_ALERTS_EVENT, onStoreChange);
+  return () =>
+    window.removeEventListener(ANALYSIS_HIDDEN_ALERTS_EVENT, onStoreChange);
+}
+
+function parseIdList(raw: unknown): number[] {
+  if (!Array.isArray(raw)) return [];
+  const out: number[] = [];
+  for (const v of raw) {
+    const n = Number(v);
+    if (Number.isInteger(n) && n >= 1) out.push(n);
+  }
+  return [...new Set(out)].sort((a, b) => a - b);
+}
+
+function invalidateStoreCache(): void {
+  storeCache = null;
+}
+
+function readStored(): StoredHiddenAlerts {
+  if (typeof document === "undefined") {
+    return { mirror: EMPTY_MIRROR, notEnded: EMPTY_NOT_ENDED };
+  }
+  const match = document.cookie.match(
+    new RegExp(`(?:^|; )${ANALYSIS_HIDDEN_ALERTS_COOKIE}=([^;]*)`),
+  );
+  const cookieValue = match?.[1] ?? "";
+  if (storeCache?.cookieValue === cookieValue) {
+    return storeCache;
+  }
+
+  let mirror = EMPTY_MIRROR;
+  let notEnded = EMPTY_NOT_ENDED;
+
+  if (cookieValue) {
+    try {
+      const parsed = JSON.parse(decodeURIComponent(cookieValue)) as unknown;
+      if (parsed && typeof parsed === "object") {
+        const o = parsed as Record<string, unknown>;
+        const m = parseIdList(o.mirror);
+        const n = parseIdList(o.notEnded);
+        if (m.length > 0) mirror = m;
+        if (n.length > 0) notEnded = n;
+      }
+    } catch {
+      // ignore corrupt cookie
+    }
+  }
+
+  storeCache = { cookieValue, mirror, notEnded };
+  return storeCache;
+}
+
+function writeStored(data: StoredHiddenAlerts): void {
+  if (typeof document === "undefined") return;
+  const value = encodeURIComponent(JSON.stringify(data));
+  document.cookie = `${ANALYSIS_HIDDEN_ALERTS_COOKIE}=${value}; path=/; max-age=${COOKIE_MAX_AGE_SEC}; SameSite=Lax`;
+  invalidateStoreCache();
+}
+
+function trimIds(ids: number[]): number[] {
+  if (ids.length <= MAX_IDS_PER_CATEGORY) return ids;
+  return ids.slice(ids.length - MAX_IDS_PER_CATEGORY);
+}
+
+/** Match ids the admin dismissed for this alert category (stable array reference). */
+export function getHiddenAnalysisMatchIds(
+  category: AnalysisAlertCategory,
+): number[] {
+  const stored = readStored();
+  return category === "mirror" ? stored.mirror : stored.notEnded;
+}
+
+/** Add match ids to the hide list for a category (persists in cookie). */
+export function hideAnalysisMatchIds(
+  category: AnalysisAlertCategory,
+  matchIds: number[],
+): void {
+  const stored = readStored();
+  const set = new Set(stored[category]);
+  for (const id of matchIds) {
+    if (Number.isInteger(id) && id >= 1) set.add(id);
+  }
+  const next = trimIds([...set].sort((a, b) => a - b));
+  writeStored({
+    mirror: category === "mirror" ? next : stored.mirror,
+    notEnded: category === "notEnded" ? next : stored.notEnded,
+  });
+  notifyHiddenAlertsChanged();
+}