diff --git a/app/services/simulations/__tests__/nhl-simulator.test.ts b/app/services/simulations/__tests__/nhl-simulator.test.ts
index 80e2029..a04ad61 100644
--- a/app/services/simulations/__tests__/nhl-simulator.test.ts
+++ b/app/services/simulations/__tests__/nhl-simulator.test.ts
@@ -1,9 +1,10 @@
-import { describe, it, expect } from "vitest";
+import { describe, it, expect, vi, beforeEach, type MockInstance } from "vitest";
 import {
   normalizeTeamName,
   getTeamData,
   eloWinProbability,
   simulateProjectedPoints,
+  NHLSimulator,
 } from "../nhl-simulator";
 
 // ─── normalizeTeamName ────────────────────────────────────────────────────────
@@ -171,3 +172,277 @@ describe("simulateProjectedPoints", () => {
     expect(avg(0.7)).toBeGreaterThan(avg(0.4));
   });
 });
+
+// ─── NHLSimulator — bracket-aware mode ───────────────────────────────────────
+
+const TEAM_IDS = Array.from({ length: 16 }, (_, i) => `team-${i + 1}`);
+
+function makeMatch(
+  round: string,
+  matchNumber: number,
+  opts: {
+    p1?: string | null;
+    p2?: string | null;
+    winnerId?: string | null;
+    loserId?: string | null;
+    isComplete?: boolean;
+  } = {}
+) {
+  return {
+    id: `${round.replace(/\s/g, "-").toLowerCase()}-m${matchNumber}`,
+    scoringEventId: "event-1",
+    round,
+    matchNumber,
+    participant1Id: opts.p1 ?? null,
+    participant2Id: opts.p2 ?? null,
+    winnerId: opts.winnerId ?? null,
+    loserId: opts.loserId ?? null,
+    isComplete: opts.isComplete ?? false,
+    isScoring: false,
+    templateRound: round,
+    seedInfo: null,
+    participant1Score: null,
+    participant2Score: null,
+    createdAt: new Date(),
+    updatedAt: new Date(),
+  };
+}
+
+/**
+ * Builds a full 16-team NHL bracket fixture:
+ *   R1: 8 matches (Wild Card, matchNumbers 1–8)
+ *   R2: 4 matches (Divisional, matchNumbers 1–4) — participants null (filled from R1 winners)
+ *   R3: 2 matches (Conference Finals, matchNumbers 1–2)
+ *   Final: 1 match (Stanley Cup, matchNumber 1)
+ */
+function buildFullNHLBracket() {
+  const t = TEAM_IDS;
+  return [
+    makeMatch("Wild Card", 1, { p1: t[0],  p2: t[15] }),
+    makeMatch("Wild Card", 2, { p1: t[1],  p2: t[14] }),
+    makeMatch("Wild Card", 3, { p1: t[2],  p2: t[13] }),
+    makeMatch("Wild Card", 4, { p1: t[3],  p2: t[12] }),
+    makeMatch("Wild Card", 5, { p1: t[4],  p2: t[11] }),
+    makeMatch("Wild Card", 6, { p1: t[5],  p2: t[10] }),
+    makeMatch("Wild Card", 7, { p1: t[6],  p2: t[9]  }),
+    makeMatch("Wild Card", 8, { p1: t[7],  p2: t[8]  }),
+    makeMatch("Divisional", 1),
+    makeMatch("Divisional", 2),
+    makeMatch("Divisional", 3),
+    makeMatch("Divisional", 4),
+    makeMatch("Conference Finals", 1),
+    makeMatch("Conference Finals", 2),
+    makeMatch("Stanley Cup", 1),
+  ];
+}
+
+vi.mock("~/database/context", () => ({
+  database: vi.fn(),
+}));
+
+vi.mock("~/models/regular-season-standings", () => ({
+  getRegularSeasonStandings: vi.fn().mockResolvedValue([]),
+}));
+
+describe("NHLSimulator — bracket-aware mode", () => {
+  let mockDb: {
+    query: {
+      scoringEvents: { findFirst: MockInstance };
+      playoffMatches: { findMany: MockInstance };
+    };
+    select: MockInstance;
+  };
+
+  beforeEach(async () => {
+    const { database } = await import("~/database/context");
+
+    mockDb = {
+      query: {
+        scoringEvents: { findFirst: vi.fn() },
+        playoffMatches: { findMany: vi.fn() },
+      },
+      select: vi.fn().mockReturnValue({
+        from: vi.fn().mockReturnValue({
+          where: vi.fn().mockResolvedValue(
+            TEAM_IDS.map((id) => ({ id, name: id }))
+          ),
+        }),
+      }),
+    };
+
+    (database as unknown as MockInstance).mockReturnValue(mockDb);
+
+    mockDb.query.scoringEvents.findFirst.mockResolvedValue({
+      id: "event-1",
+      sportsSeasonId: "season-1",
+      eventType: "playoff_game",
+    });
+  });
+
+  it("falls back to season-projection when no bracket event exists", async () => {
+    mockDb.query.scoringEvents.findFirst.mockResolvedValue(null);
+
+    const sim = new NHLSimulator();
+    // Season-projection fails: unknown team IDs → no division data → division check throws
+    await expect(sim.simulate("season-1")).rejects.toThrow(/Each division needs at least 3/);
+  });
+
+  it("falls back to season-projection when bracket matches have no participants", async () => {
+    const emptyMatches = buildFullNHLBracket().map((m) => ({
+      ...m,
+      participant1Id: null,
+      participant2Id: null,
+    }));
+    mockDb.query.playoffMatches.findMany.mockResolvedValue(emptyMatches);
+
+    const sim = new NHLSimulator();
+    await expect(sim.simulate("season-1")).rejects.toThrow(/Each division needs at least 3/);
+  });
+
+  it("throws if bracket has fewer than 4 rounds", async () => {
+    const oneRound = Array.from({ length: 8 }, (_, i) =>
+      makeMatch("Wild Card", i + 1, { p1: TEAM_IDS[i], p2: TEAM_IDS[i + 8] ?? TEAM_IDS[0] })
+    );
+    mockDb.query.playoffMatches.findMany.mockResolvedValue(oneRound);
+
+    const sim = new NHLSimulator();
+    await expect(sim.simulate("season-1")).rejects.toThrow(/unexpected structure/);
+  });
+
+  it("throws if R1 has wrong match count", async () => {
+    const shortR1 = [
+      ...Array.from({ length: 4 }, (_, i) =>
+        makeMatch("Wild Card", i + 1, { p1: TEAM_IDS[i], p2: TEAM_IDS[i + 4] })
+      ),
+      makeMatch("Divisional", 1),
+      makeMatch("Divisional", 2),
+      makeMatch("Conference Finals", 1),
+      makeMatch("Stanley Cup", 1),
+    ];
+    mockDb.query.playoffMatches.findMany.mockResolvedValue(shortR1);
+
+    const sim = new NHLSimulator();
+    await expect(sim.simulate("season-1")).rejects.toThrow(/Expected 8 first-round matches/);
+  });
+
+  it("throws if an R1 participant slot is missing", async () => {
+    const matches = buildFullNHLBracket();
+    const r1m3 = matches.find((m) => m.round === "Wild Card" && m.matchNumber === 3)!;
+    r1m3.participant2Id = null;
+
+    mockDb.query.playoffMatches.findMany.mockResolvedValue(matches);
+
+    const sim = new NHLSimulator();
+    await expect(sim.simulate("season-1")).rejects.toThrow(/missing participants/);
+  });
+
+  it("returns results for all 16 participants", async () => {
+    mockDb.query.playoffMatches.findMany.mockResolvedValue(buildFullNHLBracket());
+
+    const sim = new NHLSimulator();
+    const results = await sim.simulate("season-1");
+
+    expect(results).toHaveLength(16);
+  });
+
+  it("each probability column sums to 1.0 across all 16 participants", async () => {
+    mockDb.query.playoffMatches.findMany.mockResolvedValue(buildFullNHLBracket());
+
+    const sim = new NHLSimulator();
+    const results = await sim.simulate("season-1");
+
+    const keys = [
+      "probFirst", "probSecond", "probThird", "probFourth",
+      "probFifth", "probSixth", "probSeventh", "probEighth",
+    ] as const;
+
+    for (const key of keys) {
+      const colSum = results.reduce((s, r) => s + r.probabilities[key], 0);
+      expect(colSum, `column ${key} should sum to 1`).toBeCloseTo(1.0, 1);
+    }
+  });
+
+  it("all probabilities are non-negative", async () => {
+    mockDb.query.playoffMatches.findMany.mockResolvedValue(buildFullNHLBracket());
+
+    const sim = new NHLSimulator();
+    const results = await sim.simulate("season-1");
+
+    for (const r of results) {
+      for (const v of Object.values(r.probabilities)) {
+        expect(v).toBeGreaterThanOrEqual(0);
+      }
+    }
+  });
+
+  it("champion has probFirst=1 when bracket is fully decided", async () => {
+    const t = TEAM_IDS;
+    const matches = buildFullNHLBracket();
+
+    // R1: p1 always wins
+    const r1 = matches.filter((m) => m.round === "Wild Card");
+    for (const m of r1) {
+      m.winnerId = m.participant1Id;
+      m.loserId  = m.participant2Id;
+      m.isComplete = true;
+    }
+    const r1Winners = r1.map((m) => m.winnerId!);
+
+    // R2: fill from R1 winners, p1 always wins
+    const r2 = matches.filter((m) => m.round === "Divisional");
+    for (let i = 0; i < 4; i++) {
+      r2[i].participant1Id = r1Winners[i * 2];
+      r2[i].participant2Id = r1Winners[i * 2 + 1];
+      r2[i].winnerId = r2[i].participant1Id;
+      r2[i].loserId  = r2[i].participant2Id;
+      r2[i].isComplete = true;
+    }
+    const r2Winners = r2.map((m) => m.winnerId!);
+
+    // R3: fill from R2 winners, p1 always wins
+    const r3 = matches.filter((m) => m.round === "Conference Finals");
+    for (let i = 0; i < 2; i++) {
+      r3[i].participant1Id = r2Winners[i * 2];
+      r3[i].participant2Id = r2Winners[i * 2 + 1];
+      r3[i].winnerId = r3[i].participant1Id;
+      r3[i].loserId  = r3[i].participant2Id;
+      r3[i].isComplete = true;
+    }
+    const r3Winners = r3.map((m) => m.winnerId!);
+
+    // Final: t[0] vs t[1], t[0] wins
+    const champion = t[0];
+    const final = matches.find((m) => m.round === "Stanley Cup")!;
+    final.participant1Id = r3Winners[0];
+    final.participant2Id = r3Winners[1];
+    final.winnerId = champion;
+    final.loserId  = r3Winners[1];
+    final.isComplete = true;
+
+    mockDb.query.playoffMatches.findMany.mockResolvedValue(matches);
+
+    const sim = new NHLSimulator();
+    const results = await sim.simulate("season-1");
+
+    const champResult = results.find((r) => r.participantId === champion);
+    expect(champResult, "champion result should exist").toBeDefined();
+    expect(champResult?.probabilities.probFirst).toBeCloseTo(1.0, 3);
+
+    for (const r of results) {
+      if (r.participantId !== champion) {
+        expect(r.probabilities.probFirst).toBeCloseTo(0, 3);
+      }
+    }
+  });
+
+  it("uses source 'nhl_bracket_monte_carlo' on all results", async () => {
+    mockDb.query.playoffMatches.findMany.mockResolvedValue(buildFullNHLBracket());
+
+    const sim = new NHLSimulator();
+    const results = await sim.simulate("season-1");
+
+    for (const r of results) {
+      expect(r.source).toBe("nhl_bracket_monte_carlo");
+    }
+  });
+});
diff --git a/app/services/simulations/__tests__/wnba-simulator.test.ts b/app/services/simulations/__tests__/wnba-simulator.test.ts
index 1d6a20a..36d6fac 100644
--- a/app/services/simulations/__tests__/wnba-simulator.test.ts
+++ b/app/services/simulations/__tests__/wnba-simulator.test.ts
@@ -80,6 +80,26 @@ describe("resolveElo", () => {
   it("futures mode with no futures: falls back to 1500", () => {
     expect(resolveElo(8, null, false)).toBe(1500);
   });
+
+  it("sourceElo overrides SRS when in SRS mode", () => {
+    expect(resolveElo(5, 1600, true, 1750)).toBe(1750);
+  });
+
+  it("sourceElo overrides futures when not in SRS mode", () => {
+    expect(resolveElo(null, 1600, false, 1750)).toBe(1750);
+  });
+
+  it("sourceElo overrides 1500 fallback when all other signals are absent", () => {
+    expect(resolveElo(null, null, false, 1700)).toBe(1700);
+  });
+
+  it("null sourceElo falls through to normal priority chain", () => {
+    expect(resolveElo(5, 1600, true, null)).toBe(srsToElo(5));
+  });
+
+  it("undefined sourceElo falls through to normal priority chain", () => {
+    expect(resolveElo(null, 1620, false, undefined)).toBe(1620);
+  });
 });
 
 // ─── simSeriesN ───────────────────────────────────────────────────────────────
diff --git a/app/services/simulations/nhl-simulator.ts b/app/services/simulations/nhl-simulator.ts
index af175dd..5891634 100644
--- a/app/services/simulations/nhl-simulator.ts
+++ b/app/services/simulations/nhl-simulator.ts
@@ -607,6 +607,16 @@ export class NHLSimulator implements Simulator {
       );
     }
 
+    // Validate all R1 matches have participants before entering the hot loop.
+    for (const m of r1Matches) {
+      if (!m.participant1Id || !m.participant2Id) {
+        throw new Error(
+          `Round 1 match ${m.matchNumber} is missing participants. ` +
+            `Seed all 16 teams into the bracket before running simulation.`
+        );
+      }
+    }
+
     // Load all participants and EV data in parallel.
     const [participantRows, evRows] = await Promise.all([
       db
@@ -624,7 +634,6 @@ export class NHLSimulator implements Simulator {
     ]);
 
     const allParticipantIds = participantRows.map((r) => r.id);
-    const nameById = new Map(participantRows.map((r) => [r.id, r.name]));
 
     const dbEloMap = new Map<string, number>();
     for (const row of evRows) {