diff --git a/src/server/routers/analytics.ts b/src/server/routers/analytics.ts
index 46fd950..1c8aa90 100644
--- a/src/server/routers/analytics.ts
+++ b/src/server/routers/analytics.ts
@@ -1368,7 +1368,7 @@ export const analyticsRouter = router({
    * Read-only combined endpoint to avoid multiple round-trips.
    */
   getProjectDetail: observerProcedure
-    .input(z.object({ id: z.string() }))
+    .input(z.object({ id: z.string(), roundId: z.string().optional() }))
     .query(async ({ ctx, input }) => {
       const [projectRaw, projectTags, assignments, submittedEvaluations] = await Promise.all([
         ctx.prisma.project.findUniqueOrThrow({
@@ -1417,7 +1417,10 @@ export const analyticsRouter = router({
         ctx.prisma.evaluation.findMany({
           where: {
             status: 'SUBMITTED',
-            assignment: { projectId: input.id },
+            assignment: {
+              projectId: input.id,
+              ...(input.roundId ? { roundId: input.roundId } : {}),
+            },
           },
         }),
       ])
diff --git a/tests/unit/juror-balance-round-scoping.test.ts b/tests/unit/juror-balance-round-scoping.test.ts
new file mode 100644
index 0000000..7e41684
--- /dev/null
+++ b/tests/unit/juror-balance-round-scoping.test.ts
@@ -0,0 +1,72 @@
+import { afterAll, beforeAll, describe, expect, it } from 'vitest'
+import { prisma, createCaller } from '../setup'
+import {
+  createTestUser, createTestProgram, createTestCompetition, createTestRound,
+  createTestProject, createTestProjectRoundState, createTestAssignment,
+  createTestEvaluation, createTestEvaluationForm, cleanupTestData, uid,
+} from '../helpers'
+import { analyticsRouter } from '../../src/server/routers/analytics'
+
+describe('analytics.getProjectDetail round scoping', () => {
+  let programId: string
+  let admin: { id: string; email: string; role: 'SUPER_ADMIN' }
+  let projectId: string
+  let roundAId: string
+  let roundBId: string
+  const userIds: string[] = []
+
+  beforeAll(async () => {
+    const program = await createTestProgram({ name: `bal-scope-${uid()}` })
+    programId = program.id
+    const competition = await createTestCompetition(programId)
+    const roundA = await createTestRound(competition.id, { name: 'Round A', sortOrder: 0, status: 'ROUND_CLOSED' })
+    const roundB = await createTestRound(competition.id, { name: 'Round B', sortOrder: 1, status: 'ROUND_ACTIVE' })
+    roundAId = roundA.id
+    roundBId = roundB.id
+
+    const formA = await createTestEvaluationForm(roundA.id)
+    const formB = await createTestEvaluationForm(roundB.id)
+
+    const project = await createTestProject(programId)
+    projectId = project.id
+    await createTestProjectRoundState(projectId, roundA.id, { state: 'PASSED' })
+    await createTestProjectRoundState(projectId, roundB.id, { state: 'IN_PROGRESS' })
+
+    // 2 evaluations on Round A: 7.0, 8.0  (mean 7.5)
+    for (const score of [7, 8]) {
+      const juror = await createTestUser('JURY_MEMBER')
+      userIds.push(juror.id)
+      const a = await createTestAssignment(juror.id, projectId, roundA.id)
+      await createTestEvaluation(a.id, formA.id, { status: 'SUBMITTED', globalScore: score, submittedAt: new Date() })
+    }
+    // 3 evaluations on Round B: 9.0, 8.0, 8.0  (mean 8.333…)
+    for (const score of [9, 8, 8]) {
+      const juror = await createTestUser('JURY_MEMBER')
+      userIds.push(juror.id)
+      const a = await createTestAssignment(juror.id, projectId, roundB.id)
+      await createTestEvaluation(a.id, formB.id, { status: 'SUBMITTED', globalScore: score, submittedAt: new Date() })
+    }
+
+    const adminUser = await createTestUser('SUPER_ADMIN')
+    userIds.push(adminUser.id)
+    admin = { id: adminUser.id, email: adminUser.email, role: 'SUPER_ADMIN' }
+  })
+
+  afterAll(async () => {
+    await cleanupTestData(programId, userIds)
+  })
+
+  it('returns only round-B stats when roundId=roundB is passed', async () => {
+    const caller = createCaller(analyticsRouter, admin)
+    const result = await caller.getProjectDetail({ id: projectId, roundId: roundBId })
+    expect(result.stats).not.toBeNull()
+    expect(result.stats!.totalEvaluations).toBe(3)
+    expect(result.stats!.averageGlobalScore).toBeCloseTo(8.333, 2)
+  })
+
+  it('returns aggregated stats across all rounds when roundId is omitted', async () => {
+    const caller = createCaller(analyticsRouter, admin)
+    const result = await caller.getProjectDetail({ id: projectId })
+    expect(result.stats!.totalEvaluations).toBe(5)
+  })
+})