diff --git a/docs/screenshots/leftover-map-comparison-singular-desktop.png b/docs/screenshots/leftover-map-comparison-singular-desktop.png
new file mode 100644
index 000000000..8e1fac9c4
Binary files /dev/null and b/docs/screenshots/leftover-map-comparison-singular-desktop.png differ
diff --git a/docs/screenshots/leftover-map-comparison-singular-mobile.png b/docs/screenshots/leftover-map-comparison-singular-mobile.png
new file mode 100644
index 000000000..7f9bac155
Binary files /dev/null and b/docs/screenshots/leftover-map-comparison-singular-mobile.png differ
diff --git a/docs/storybook-inventory.md b/docs/storybook-inventory.md
index 26b00286f..c1b9649b6 100644
--- a/docs/storybook-inventory.md
+++ b/docs/storybook-inventory.md
@@ -5,7 +5,7 @@ operator-facing control you can click before changing product CSS.
 
 | Story | Operator next action | Token / module |
 |---|---|---|
-| `Reports/LeftoverMapPlot` | Read the leftover-map graphic display of persisted `ξ` (posts) and `ζ` (criteria), match axis ticks to those coordinates, pair-segment `d` to leftover-map distance, pair-segment `R̂` to leftover-map reconstruction, pair-segment `R̂²/R²` to leftover-map explained leftover share, pair-segment `U²/R²` to leftover-map unexplained leftover share, pair-segment `2R̂U/R²` to leftover-map cross share, pair-segment `U` to leftover-map unexplained leftover, pair-segment `R` to leftover residual, pair-segment `Y` to leftover observed, pair-segment `E` to leftover expected, and pair-segment leftover-map rank, then click a post marker to open that post. Leftover-map axes name persisted leftover-map axis share when finite. The plot names leftover-map complete-case coverage, leftover-map item complete-case coverage, leftover-map incomplete post coverage, and leftover-map incomplete item coverage when persisted. The comparison variant names leftover-map complete-case coverage under `Leftover map comparison graphic coverage` and leftover-map item complete-case coverage under `Leftover map comparison graphic item coverage` and leftover-map incomplete post coverage under `Leftover map comparison graphic incomplete posts` and leftover-map incomplete item coverage under `Leftover map comparison graphic incomplete items`. `ClosestAndFarthest`, `RankZeroOrigin`, `MissingCoordinates`, `MissingAxisShare`, `Comparison`, `ComparisonMissingCoverage`, `ComparisonMissingItemCoverage`, `ComparisonMissingIncompletePosts`, and `ComparisonMissingIncompleteItems` cover two-pair maps, rank-0 origin with 0% share, a `0` tick, `d 0.00`, `R̂ 0.00`, `R̂²/R² 0.00`, `U²/R² 0.00`, `2R̂U/R² 0.00`, `U 0.00`, `R 0.00`, `Y 0.00`, `E 0.00`, and `rank 0`, omitted plots, missing share that keeps existing leftover-map axis text, grouping comparison leftover-map graphic coverage that matches leftover map used N of M scored posts, omitted comparison graphic coverage when leftoverMapCoverageCounts fail-closes, grouping comparison leftover-map graphic item coverage that matches leftover map used N of M scored criteria, omitted comparison graphic item coverage when leftoverMapItemCoverageCounts fail-closes, grouping comparison leftover-map graphic incomplete posts that matches leftover map dropped N incomplete posts, omitted comparison graphic incomplete posts when leftoverMapIncompletePostCount fail-closes, grouping comparison leftover-map graphic incomplete items that matches leftover map dropped N incomplete criteria, and omitted comparison graphic incomplete items when leftoverMapIncompleteItemCount fail-closes. The plot does not invent a leftover score. | `LeftoverMapPlot`, `leftoverMapPlotLayout`, `leftoverMapPlotAxisShare`, `--color-primary`, `--color-palette-blue-mid` |
+| `Reports/LeftoverMapPlot` | Read the leftover-map graphic display of persisted `ξ` (posts) and `ζ` (criteria), match axis ticks to those coordinates, pair-segment `d` to leftover-map distance, pair-segment `R̂` to leftover-map reconstruction, pair-segment `R̂²/R²` to leftover-map explained leftover share, pair-segment `U²/R²` to leftover-map unexplained leftover share, pair-segment `2R̂U/R²` to leftover-map cross share, pair-segment `U` to leftover-map unexplained leftover, pair-segment `R` to leftover residual, pair-segment `Y` to leftover observed, pair-segment `E` to leftover expected, and pair-segment leftover-map rank, then click a post marker to open that post. Leftover-map axes name persisted leftover-map axis share when finite. The comparison variant keeps exact persisted σ and share together and right-bounds both axis captions inside the SVG. The plot names leftover-map complete-case coverage, leftover-map item complete-case coverage, leftover-map incomplete post coverage, and leftover-map incomplete item coverage when persisted. The comparison variant names leftover-map complete-case coverage under `Leftover map comparison graphic coverage` and leftover-map item complete-case coverage under `Leftover map comparison graphic item coverage` and leftover-map incomplete post coverage under `Leftover map comparison graphic incomplete posts` and leftover-map incomplete item coverage under `Leftover map comparison graphic incomplete items`. `ClosestAndFarthest`, `RankZeroOrigin`, `MissingCoordinates`, `MissingAxisShare`, `Comparison`, `ComparisonMissingCoverage`, `ComparisonMissingItemCoverage`, `ComparisonMissingIncompletePosts`, and `ComparisonMissingIncompleteItems` cover two-pair maps, rank-0 origin with 0% share, a `0` tick, `d 0.00`, `R̂ 0.00`, `R̂²/R² 0.00`, `U²/R² 0.00`, `2R̂U/R² 0.00`, `U 0.00`, `R 0.00`, `Y 0.00`, `E 0.00`, and `rank 0`, omitted plots, missing share that keeps existing leftover-map axis text, grouping comparison leftover-map graphic coverage that matches leftover map used N of M scored posts, omitted comparison graphic coverage when leftoverMapCoverageCounts fail-closes, grouping comparison leftover-map graphic item coverage that matches leftover map used N of M scored criteria, omitted comparison graphic item coverage when leftoverMapItemCoverageCounts fail-closes, grouping comparison leftover-map graphic incomplete posts that matches leftover map dropped N incomplete posts, omitted comparison graphic incomplete posts when leftoverMapIncompletePostCount fail-closes, grouping comparison leftover-map graphic incomplete items that matches leftover map dropped N incomplete criteria, and omitted comparison graphic incomplete items when leftoverMapIncompleteItemCount fail-closes. Desktop and 390×844 evidence is retained in `docs/screenshots/leftover-map-comparison-singular-{desktop,mobile}.png`. The plot does not invent a leftover score. | `LeftoverMapPlot`, `leftoverMapPlotLayout`, `leftoverMapPlotAxisShare`, `--color-primary`, `--color-palette-blue-mid` |
 | `Reports/LeftoverPairList` | Read closest/farthest leftover pairs with named `R`, `Y`/`E`, rank, `U`, `s`, `e`, `x`, `R̂`, `ξ`/`ζ`, and `d`, then open that post. The leftover-map graphic display sits above the pair buttons when coordinates are finite, leftover-map axes name persisted leftover-map axis share, leftover-map axis ticks name persisted coordinates, pair segments name persisted leftover-map distance, pair segments name persisted leftover-map reconstruction, pair segments name persisted leftover-map explained leftover share, pair segments name persisted leftover-map unexplained leftover share, pair segments name persisted leftover-map cross share, pair segments name persisted leftover-map unexplained leftover, pair segments name persisted leftover residual, pair segments name persisted leftover observed, pair segments name persisted leftover expected, and pair segments name persisted leftover-map rank. The pair-list note names leftover-map complete-case coverage only when leftoverMapCoverageCounts returns usable complete-case integers, leftover-map item complete-case coverage, leftover-map incomplete post coverage, and leftover-map incomplete item coverage when persisted. The grouping comparison strip names leftover-map complete-case coverage, leftover-map item complete-case coverage, leftover-map incomplete post coverage, and leftover-map incomplete item coverage with distinct comparison labels when leftoverMapCoverageCounts / leftoverMapItemCoverageCounts / leftoverMapIncompletePostCount / leftoverMapIncompleteItemCount return usable integers. | `LeftoverPairList`, `LeftoverMapPlot`, `ticket-list`, `post-badge` |
 | `Workspace/OperationsDashboard` | Compare Event and post counts, inspect external-information coverage, then open the cited source behind a claim, handover, or repeat-issue fact. `EvidenceReady`, `NarrowViewport`, `AnalysisPendingAndMissingEvidence`, `AnalysisFailed`, and `LoadError` cover populated, mobile, unavailable-evidence, analysis-pending, retryable failure, and transport-error states. | `--color-dashboard-*`, `OperationsDashboard` |
 | `Post/SimilarVocPanel` | Compare ontology/semantic similar VOC and prior action evidence, then open the source; unavailable states show no fabricated TEPP theta or weight. | `SimilarVocPanel.css`, `SimilarVocPanel` |
diff --git a/frontend/src/App.test.tsx b/frontend/src/App.test.tsx
index 544f89488..153bb9af2 100644
--- a/frontend/src/App.test.tsx
+++ b/frontend/src/App.test.tsx
@@ -4197,8 +4197,8 @@ describe("App, authenticated", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic")).toBeInTheDocument();
     expect(screen.getByText("leftover-map axis 1 (82%)")).toBeInTheDocument();
     expect(screen.getByText("leftover-map axis 2 (18%)")).toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 2 (18%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 2 (σ 0.86, 18%)")).toBeInTheDocument();
     expect(
       screen.getAllByRole("button", {
         name: /open leftover-map post public post at ξ \(\+0\.50, \+0\.10\)/i,
@@ -4322,12 +4322,12 @@ describe("App, authenticated", () => {
     ).not.toBeInTheDocument();
     expect(
       within(screen.getByLabelText("Grouping comparison")).getByText(
-        "leftover map comparison axis 1 (82%)",
+        "leftover map comparison axis 1 (σ 1.84, 82%)",
       ),
     ).toBeInTheDocument();
     expect(
       within(screen.getByLabelText("Grouping comparison")).getByText(
-        "leftover map comparison axis 2 (18%)",
+        "leftover map comparison axis 2 (σ 0.86, 18%)",
       ),
     ).toBeInTheDocument();
     expect(
diff --git a/frontend/src/components/LeftoverMapPlot.test.tsx b/frontend/src/components/LeftoverMapPlot.test.tsx
index 56258c883..42e6bf0f6 100644
--- a/frontend/src/components/LeftoverMapPlot.test.tsx
+++ b/frontend/src/components/LeftoverMapPlot.test.tsx
@@ -843,8 +843,16 @@ describe("LeftoverMapPlot", () => {
         "Leftover map comparison graphic of already-named coordinates. Click a post marker to open that post. The plot does not invent a leftover score.",
       ),
     ).toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 2 (18%)")).toBeInTheDocument();
+    const axis1 = screen.getByText(
+      "leftover map comparison axis 1 (σ 1.84, 82%)",
+    );
+    const axis2 = screen.getByText(
+      "leftover map comparison axis 2 (σ 0.86, 18%)",
+    );
+    expect(axis1).toHaveAttribute("x", "472");
+    expect(axis1).toHaveAttribute("text-anchor", "end");
+    expect(axis2).toHaveAttribute("x", "472");
+    expect(axis2).toHaveAttribute("text-anchor", "end");
     expect(screen.queryByText("leftover-map axis 1 (82%)")).not.toBeInTheDocument();
     expect(screen.queryByText("leftover-map axis 2 (18%)")).not.toBeInTheDocument();
   });
@@ -861,9 +869,11 @@ describe("LeftoverMapPlot", () => {
         variant="comparison"
       />,
     );
-    expect(screen.getByText("leftover map comparison axis 1")).toBeInTheDocument();
+    expect(
+      screen.getByText("leftover map comparison axis 1 (σ 1.84)"),
+    ).toBeInTheDocument();
     expect(screen.getByText("leftover map comparison axis 2")).toBeInTheDocument();
-    expect(screen.queryByText(/leftover map comparison axis 1 \(/)).not.toBeInTheDocument();
+    expect(screen.queryByText(/leftover map comparison axis 1 \(σ 1\.84,/)).not.toBeInTheDocument();
     expect(screen.queryByText(/leftover map comparison axis 2 \(/)).not.toBeInTheDocument();
     expect(screen.queryByText("leftover-map axis 1")).not.toBeInTheDocument();
     expect(screen.queryByText("leftover-map axis 2")).not.toBeInTheDocument();
@@ -890,8 +900,12 @@ describe("LeftoverMapPlot", () => {
         variant="comparison"
       />,
     );
-    expect(screen.getByText("leftover map comparison axis 1 (0%)")).toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 2 (0%)")).toBeInTheDocument();
+    expect(
+      screen.getByText("leftover map comparison axis 1 (σ 0.00, 0%)"),
+    ).toBeInTheDocument();
+    expect(
+      screen.getByText("leftover map comparison axis 2 (σ 0.00, 0%)"),
+    ).toBeInTheDocument();
   });
 
   it("names leftover-map coverage on the comparison graphic with a distinct accessible name", () => {
@@ -935,8 +949,8 @@ describe("LeftoverMapPlot", () => {
     expect(screen.queryByLabelText("Leftover map comparison incomplete posts")).not.toBeInTheDocument();
     expect(screen.queryByLabelText("Leftover-map graphic incomplete items")).not.toBeInTheDocument();
     expect(screen.queryByLabelText("Leftover map comparison incomplete items")).not.toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 2 (18%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 2 (σ 0.86, 18%)")).toBeInTheDocument();
   });
 
   it("omits leftover-map comparison graphic coverage when coverage is missing or not usable", () => {
@@ -954,7 +968,7 @@ describe("LeftoverMapPlot", () => {
     );
     expect(screen.queryByLabelText("Leftover map comparison graphic coverage")).not.toBeInTheDocument();
     expect(screen.getByLabelText("Leftover map comparison graphic")).toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
     rerender(
       <LeftoverMapPlot
         pairs={PAIRS}
@@ -980,7 +994,7 @@ describe("LeftoverMapPlot", () => {
       "Leftover map used 2 of 2 scored criteria (complete-case)",
     );
     expect(screen.queryByLabelText("Leftover-map graphic coverage")).not.toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("omits leftover-map comparison graphic item coverage when item coverage is missing or not usable", () => {
@@ -1009,7 +1023,7 @@ describe("LeftoverMapPlot", () => {
     );
     expect(screen.queryByLabelText("Leftover map comparison graphic item coverage")).not.toBeInTheDocument();
     expect(screen.queryByLabelText("Leftover-map graphic item coverage")).not.toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
     rerender(
       <LeftoverMapPlot
         pairs={PAIRS}
@@ -1035,7 +1049,7 @@ describe("LeftoverMapPlot", () => {
     );
     expect(screen.queryByLabelText("Leftover map comparison graphic item coverage")).not.toBeInTheDocument();
     expect(screen.queryByLabelText("Leftover-map graphic item coverage")).not.toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("omits leftover-map comparison graphic incomplete posts when incomplete post coverage is missing or not usable", () => {
@@ -1067,7 +1081,7 @@ describe("LeftoverMapPlot", () => {
     );
     expect(screen.queryByLabelText("Leftover map comparison graphic incomplete posts")).not.toBeInTheDocument();
     expect(screen.queryByLabelText("Leftover-map graphic incomplete posts")).not.toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
     rerender(
       <LeftoverMapPlot
         pairs={PAIRS}
@@ -1093,7 +1107,7 @@ describe("LeftoverMapPlot", () => {
     );
     expect(screen.queryByLabelText("Leftover map comparison graphic incomplete posts")).not.toBeInTheDocument();
     expect(screen.queryByLabelText("Leftover-map graphic incomplete posts")).not.toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("omits leftover-map comparison graphic incomplete items when incomplete item coverage is missing or not usable", () => {
@@ -1128,7 +1142,7 @@ describe("LeftoverMapPlot", () => {
     );
     expect(screen.queryByLabelText("Leftover map comparison graphic incomplete items")).not.toBeInTheDocument();
     expect(screen.queryByLabelText("Leftover-map graphic incomplete items")).not.toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
     rerender(
       <LeftoverMapPlot
         pairs={PAIRS}
@@ -1157,7 +1171,7 @@ describe("LeftoverMapPlot", () => {
     );
     expect(screen.queryByLabelText("Leftover map comparison graphic incomplete items")).not.toBeInTheDocument();
     expect(screen.queryByLabelText("Leftover-map graphic incomplete items")).not.toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("names leftover-map comparison graphic coverage 0 of M on a rank-0 origin when that persisted used count is a non-negative integer", () => {
@@ -1209,8 +1223,8 @@ describe("LeftoverMapPlot", () => {
     expect(screen.queryByLabelText("Leftover-map graphic item coverage")).not.toBeInTheDocument();
     expect(screen.queryByLabelText("Leftover-map graphic incomplete posts")).not.toBeInTheDocument();
     expect(screen.queryByLabelText("Leftover-map graphic incomplete items")).not.toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 1 (0%)")).toBeInTheDocument();
-    expect(screen.getByText("leftover map comparison axis 2 (0%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 0.00, 0%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 2 (σ 0.00, 0%)")).toBeInTheDocument();
   });
 
   it("names leftover-map reconstruction on the comparison graphic with a distinct accessible name", () => {
@@ -1246,7 +1260,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic incomplete items")).toHaveTextContent(
       "Leftover map dropped 0 incomplete criteria",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("omits leftover-map comparison graphic reconstruction when R̂ is missing or not usable", () => {
@@ -1280,7 +1294,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 2 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("names rank-0 origin reconstruction on the comparison graphic when that persisted value is finite", () => {
@@ -1323,7 +1337,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 0 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (0%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 0.00, 0%)")).toBeInTheDocument();
   });
 
   it("names leftover-map explained leftover share on the comparison graphic with a distinct accessible name", () => {
@@ -1359,7 +1373,7 @@ describe("LeftoverMapPlot", () => {
     expect(
       screen.getByLabelText("leftover map comparison graphic reconstruction R̂ +0.25"),
     ).toHaveTextContent("R̂ +0.25");
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("omits leftover-map comparison graphic explained leftover share when e is missing or not usable", () => {
@@ -1396,7 +1410,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 2 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("names rank-0 origin explained leftover share on the comparison graphic when that persisted value is finite", () => {
@@ -1443,7 +1457,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 0 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (0%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 0.00, 0%)")).toBeInTheDocument();
   });
 
   it("names leftover-map unexplained leftover share on the comparison graphic with a distinct accessible name", () => {
@@ -1482,7 +1496,7 @@ describe("LeftoverMapPlot", () => {
     expect(
       screen.getByLabelText("leftover map comparison graphic reconstruction R̂ +0.25"),
     ).toHaveTextContent("R̂ +0.25");
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("omits leftover-map comparison graphic unexplained leftover share when s is missing or not usable", () => {
@@ -1522,7 +1536,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 2 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("names rank-0 origin unexplained leftover share on the comparison graphic when that persisted value is finite", () => {
@@ -1573,7 +1587,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 0 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (0%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 0.00, 0%)")).toBeInTheDocument();
   });
 
   it("names leftover-map cross share on the comparison graphic with a distinct accessible name", () => {
@@ -1615,7 +1629,7 @@ describe("LeftoverMapPlot", () => {
     expect(
       screen.getByLabelText("leftover map comparison graphic reconstruction R̂ +0.25"),
     ).toHaveTextContent("R̂ +0.25");
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("omits leftover-map comparison graphic cross share when x is missing or not usable", () => {
@@ -1658,7 +1672,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 2 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("names rank-0 origin leftover-map cross share on the comparison graphic when that persisted value is finite", () => {
@@ -1713,7 +1727,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 0 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (0%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 0.00, 0%)")).toBeInTheDocument();
   });
 
   it("names leftover-map unexplained leftover on the comparison graphic with a distinct accessible name", () => {
@@ -1758,7 +1772,7 @@ describe("LeftoverMapPlot", () => {
     expect(
       screen.getByLabelText("leftover map comparison graphic reconstruction R̂ +0.25"),
     ).toHaveTextContent("R̂ +0.25");
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("omits leftover-map comparison graphic unexplained leftover when U is missing or not usable", () => {
@@ -1804,7 +1818,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 2 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("names rank-0 origin leftover-map unexplained leftover on the comparison graphic when that persisted value is finite", () => {
@@ -1863,7 +1877,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 0 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (0%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 0.00, 0%)")).toBeInTheDocument();
   });
 
   it("names leftover residual on the comparison graphic with a distinct accessible name", () => {
@@ -1911,7 +1925,7 @@ describe("LeftoverMapPlot", () => {
     expect(
       screen.getByLabelText("leftover map comparison graphic reconstruction R̂ +0.25"),
     ).toHaveTextContent("R̂ +0.25");
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("omits leftover-map comparison graphic leftover residual when R is missing or not usable", () => {
@@ -1960,7 +1974,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 2 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("names rank-0 origin leftover residual on the comparison graphic when that persisted value is finite", () => {
@@ -2022,7 +2036,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 0 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (0%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 0.00, 0%)")).toBeInTheDocument();
   });
 
   it("names leftover observed on the comparison graphic with a distinct accessible name", () => {
@@ -2073,7 +2087,7 @@ describe("LeftoverMapPlot", () => {
     expect(
       screen.getByLabelText("leftover map comparison graphic reconstruction R̂ +0.25"),
     ).toHaveTextContent("R̂ +0.25");
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("omits leftover-map comparison graphic leftover observed when Y is missing or not usable", () => {
@@ -2125,7 +2139,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 2 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("names rank-0 origin leftover observed on the comparison graphic when that persisted value is finite", () => {
@@ -2191,7 +2205,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 0 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (0%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 0.00, 0%)")).toBeInTheDocument();
   });
 
   it("names leftover expected on the comparison graphic with a distinct accessible name", () => {
@@ -2241,7 +2255,7 @@ describe("LeftoverMapPlot", () => {
     expect(
       screen.getByLabelText("leftover map comparison graphic reconstruction R̂ +0.25"),
     ).toHaveTextContent("R̂ +0.25");
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("omits leftover-map comparison graphic leftover expected when E is missing or not usable", () => {
@@ -2296,7 +2310,7 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 2 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (82%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 1.84, 82%)")).toBeInTheDocument();
   });
 
   it("names rank-0 origin leftover expected on the comparison graphic when that persisted value is finite", () => {
@@ -2366,6 +2380,6 @@ describe("LeftoverMapPlot", () => {
     expect(screen.getByLabelText("Leftover map comparison graphic coverage")).toHaveTextContent(
       "Leftover map used 0 of 3 scored posts (complete-case)",
     );
-    expect(screen.getByText("leftover map comparison axis 1 (0%)")).toBeInTheDocument();
+    expect(screen.getByText("leftover map comparison axis 1 (σ 0.00, 0%)")).toBeInTheDocument();
   });
 });
diff --git a/frontend/src/components/LeftoverMapPlot.tsx b/frontend/src/components/LeftoverMapPlot.tsx
index ef6ab3044..e199fab76 100644
--- a/frontend/src/components/LeftoverMapPlot.tsx
+++ b/frontend/src/components/LeftoverMapPlot.tsx
@@ -27,6 +27,12 @@ import {
   LEFTOVER_MAP_COMPARE_PLOT_AXIS_SHARE,
   LEFTOVER_MAP_PLOT_AXIS_SHARE,
 } from "../leftoverMapPlotAxisShare";
+import {
+  formatLeftoverMapPlotAxisSingular,
+  leftoverSingularForAxis,
+  LEFTOVER_MAP_COMPARE_PLOT_AXIS_SINGULAR,
+  LEFTOVER_MAP_COMPARE_PLOT_AXIS_SINGULAR_SHARE,
+} from "../leftoverMapPlotAxisSingular";
 import {
   firstPlottablePairForPost,
   layoutLeftoverMapPlot,
@@ -80,11 +86,24 @@ function leftoverMapPlotAxisText(
   const percent = formatLeftoverMapPlotAxisShare(
     leftoverShareForAxis(leftoverMapAxes, axisIndex),
   );
+  const singular = formatLeftoverMapPlotAxisSingular(
+    leftoverSingularForAxis(leftoverMapAxes, axisIndex),
+  );
   if (variant === "comparison") {
+    if (singular === null) {
+      if (percent === null) {
+        return t(axisIndex === 1 ? LEFTOVER_MAP_COMPARE_PLOT_AXIS_1 : LEFTOVER_MAP_COMPARE_PLOT_AXIS_2);
+      }
+      return tf(LEFTOVER_MAP_COMPARE_PLOT_AXIS_SHARE, { axis: axisIndex, share: percent });
+    }
     if (percent === null) {
-      return t(axisIndex === 1 ? LEFTOVER_MAP_COMPARE_PLOT_AXIS_1 : LEFTOVER_MAP_COMPARE_PLOT_AXIS_2);
+      return tf(LEFTOVER_MAP_COMPARE_PLOT_AXIS_SINGULAR, { axis: axisIndex, value: singular });
     }
-    return tf(LEFTOVER_MAP_COMPARE_PLOT_AXIS_SHARE, { axis: axisIndex, share: percent });
+    return tf(LEFTOVER_MAP_COMPARE_PLOT_AXIS_SINGULAR_SHARE, {
+      axis: axisIndex,
+      value: singular,
+      share: percent,
+    });
   }
   if (percent === null) {
     return t(axisIndex === 1 ? "leftover-map axis 1" : "leftover-map axis 2");
@@ -98,6 +117,9 @@ function leftoverMapPlotAxisText(
  * Person markers are posts; item markers are leftover criteria. Click a
  * post marker to open that post. Caption leftover-map axes with persisted
  * Gabriel inertia share when finite, including rank-0 zero-share axes.
+ * Comparison graphic axes additionally name finite, non-negative persisted
+ * Gabriel singular values independently of axis share; never derive one
+ * measurement from the other.
  * Axis ticks name persisted leftover-map coordinates so ξ / ζ on the
  * pair row match the plot. Pair segments name persisted leftover-map
  * distance ``d``, leftover-map reconstruction ``R̂``, leftover-map
@@ -126,8 +148,8 @@ function leftoverMapPlotAxisText(
  * caption when incomplete post coverage is missing or not a usable integer.
  * Omit that leftover-map incomplete item caption when incomplete item
  * coverage is missing or not a usable integer.
- * Omit that axis badge when share is
- * missing or non-finite and keep the existing leftover-map axis text.
+ * Omit each axis evidence badge independently when its persisted evidence is
+ * unusable and keep the remaining buyer-visible axis evidence intact.
  * Omit the plot when no pair has four finite leftover-map coordinates.
  * ADR 0304 reuses this graphic on the grouping comparison strip from
  * already-named leftover-map coordinates. ADR 0305 captions leftover-map axis
@@ -176,6 +198,8 @@ function leftoverMapPlotAxisText(
  * the same localized composition boundary rather than adding another static
  * comparison-only translation key. ADR 0320 names comparison coordinate ticks
  * through the same composition boundary, preserving localized generic tick copy.
+ * ADR 0321 adds persisted comparison-axis singular evidence without deriving it
+ * from axis share.
  * Never invent a leftover score.
  */
 export function LeftoverMapPlot({
@@ -296,7 +320,12 @@ export function LeftoverMapPlot({
           <text className="leftover-map-plot-axis-label" x={layout.width - 8} y={layout.originY - 8} textAnchor="end">
             {leftoverMapPlotAxisText(1, leftoverMapAxes, variant)}
           </text>
-          <text className="leftover-map-plot-axis-label" x={layout.originX + 8} y={16}>
+          <text
+            className="leftover-map-plot-axis-label"
+            x={layout.width - 8}
+            y={16}
+            textAnchor="end"
+          >
             {leftoverMapPlotAxisText(2, leftoverMapAxes, variant)}
           </text>
           {layout.ticks.map((tick) => (
diff --git a/frontend/src/leftoverMapPlotAxisSingular.ts b/frontend/src/leftoverMapPlotAxisSingular.ts
new file mode 100644
index 000000000..267522cbf
--- /dev/null
+++ b/frontend/src/leftoverMapPlotAxisSingular.ts
@@ -0,0 +1,39 @@
+/** Project persisted leftover-map singular-value evidence into buyer-visible axis captions. */
+
+import type { LeftoverMapAxis } from "./api";
+
+export const LEFTOVER_MAP_COMPARE_PLOT_AXIS_SINGULAR =
+  "leftover map comparison axis {axis} (σ {value})";
+
+export const LEFTOVER_MAP_COMPARE_PLOT_AXIS_SINGULAR_SHARE =
+  "leftover map comparison axis {axis} (σ {value}, {share}%)";
+
+export type LeftoverMapPlotAxisSingular = {
+  axis_index: LeftoverMapAxis["axis_index"];
+  leftover_singular_value?: LeftoverMapAxis["leftover_singular_value"] | null;
+};
+
+export function leftoverSingularForAxis(
+  axes: ReadonlyArray<LeftoverMapPlotAxisSingular> | null | undefined,
+  axisIndex: number,
+): number | null {
+  const axis = axes?.find((candidate) => candidate.axis_index === axisIndex);
+  if (
+    axis == null ||
+    axis.leftover_singular_value == null ||
+    !Number.isFinite(axis.leftover_singular_value) ||
+    axis.leftover_singular_value < 0
+  ) {
+    return null;
+  }
+  return axis.leftover_singular_value;
+}
+
+export function formatLeftoverMapPlotAxisSingular(
+  leftoverSingular: number | null | undefined,
+): string | null {
+  if (leftoverSingular == null || !Number.isFinite(leftoverSingular) || leftoverSingular < 0) {
+    return null;
+  }
+  return leftoverSingular.toFixed(2);
+}
diff --git a/tests/test_grouping_comparison_graphic_singular_contract.py b/tests/test_grouping_comparison_graphic_singular_contract.py
new file mode 100644
index 000000000..d153db856
--- /dev/null
+++ b/tests/test_grouping_comparison_graphic_singular_contract.py
@@ -0,0 +1,70 @@
+"""Executable contract for persisted singular values on the comparison graphic."""
+
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+PLOT_SOURCE = ROOT / "frontend" / "src" / "components" / "LeftoverMapPlot.tsx"
+SINGULAR_SOURCE = ROOT / "frontend" / "src" / "leftoverMapPlotAxisSingular.ts"
+APP_TEST_SOURCE = ROOT / "frontend" / "src" / "App.test.tsx"
+
+
+def test_comparison_graphic_has_distinct_persisted_singular_value_copy() -> None:
+    """Comparison-axis σ copy must remain distinct from report, strip, share, and tick copy."""
+    assert SINGULAR_SOURCE.exists(), (
+        "comparison graphic singular-value helper is missing; do not infer σ from axis share"
+    )
+    singular_source = SINGULAR_SOURCE.read_text(encoding="utf-8")
+    plot_source = PLOT_SOURCE.read_text(encoding="utf-8")
+
+    assert (
+        'export const LEFTOVER_MAP_COMPARE_PLOT_AXIS_SINGULAR =\n'
+        '  "leftover map comparison axis {axis} (σ {value})";'
+        in singular_source
+    )
+    assert (
+        'export const LEFTOVER_MAP_COMPARE_PLOT_AXIS_SINGULAR_SHARE =\n'
+        '  "leftover map comparison axis {axis} (σ {value}, {share}%)";'
+        in singular_source
+    )
+    assert "LEFTOVER_MAP_COMPARE_PLOT_AXIS_SINGULAR" in plot_source
+    assert "LEFTOVER_MAP_COMPARE_PLOT_AXIS_SINGULAR_SHARE" in plot_source
+
+
+def test_singular_value_is_read_from_axis_evidence_and_fails_closed() -> None:
+    """Persisted σ=0 stays explicit; missing, non-finite, or negative σ omits independently."""
+    assert SINGULAR_SOURCE.exists(), "persisted singular-value projection helper is missing"
+    singular_source = SINGULAR_SOURCE.read_text(encoding="utf-8")
+
+    assert "leftover_singular_value" in singular_source
+    assert "Number.isFinite" in singular_source
+    assert "< 0" in singular_source
+    assert "return null" in singular_source
+    assert ".toFixed(2)" in singular_source
+    assert "leftover_share" not in singular_source
+    assert "Math.max" not in singular_source
+    assert "Math.min" not in singular_source
+
+
+def test_app_acceptance_requires_exact_comparison_sigma_and_share_copy() -> None:
+    """App acceptance must assert the persisted comparison σ and share together, exactly."""
+    app_test_source = APP_TEST_SOURCE.read_text(encoding="utf-8")
+
+    stale_share_only = (
+        '"leftover map comparison axis 1 (82%)"',
+        '"leftover map comparison axis 2 (18%)"',
+    )
+    expected_sigma_share = (
+        '"leftover map comparison axis 1 (σ 1.84, 82%)"',
+        '"leftover map comparison axis 2 (σ 0.86, 18%)"',
+    )
+
+    for stale_copy in stale_share_only:
+        assert stale_copy not in app_test_source, (
+            "comparison-axis App acceptance still asserts pre-ADR-0321 share-only copy"
+        )
+    for expected_copy in expected_sigma_share:
+        assert app_test_source.count(expected_copy) >= 2, (
+            "comparison-axis App acceptance must cover exact σ+share copy in both report and "
+            "grouping-comparison integration paths"
+        )