Add time-at-top tracking to leaderboard

Tracks leadership changes in top_history.json and computes the fraction
of competition time each team has held the #1 position. Displayed as a
percentage with a bar in the leaderboard table.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: ihh

.github/workflows/validate.yml

@@ -89,6 +89,7 @@ jobs:
         run: |
           mkdir -p docs/scores
           cp leaderboard.json docs/ 2>/dev/null || true
+          cp top_history.json docs/ 2>/dev/null || true
           cp scores/*.json docs/scores/ 2>/dev/null || true
           # Remove stale docs scores
           for f in docs/scores/*.json; do
@@ -109,5 +110,7 @@ jobs:
           add-paths: |
             scores/
             leaderboard.json
+            top_history.json
             docs/leaderboard.json
+            docs/top_history.json
             docs/scores/

ci/rebuild_leaderboard.py

@@ -83,6 +83,9 @@ def main():
     docs_scores = docs_dir / "scores"
     docs_scores.mkdir(parents=True, exist_ok=True)
     shutil.copy2(leaderboard_path, docs_dir / "leaderboard.json")
+    history_path = root / "top_history.json"
+    if history_path.exists():
+        shutil.copy2(history_path, docs_dir / "top_history.json")
     for f in scores_dir.glob("*.json"):
         shutil.copy2(f, docs_scores / f.name)
     # Remove stale docs scores

ci/validate.py

@@ -167,6 +167,48 @@ def _build_report(
     }
 
 
+def _update_top_history(history_path: Path, leader: str, score: float) -> list[dict]:
+    """Append to top_history.json if the leader changed. Returns the history."""
+    history: list[dict] = []
+    if history_path.exists():
+        try:
+            history = json.loads(history_path.read_text())
+        except (json.JSONDecodeError, ValueError):
+            history = []
+
+    now = datetime.now(timezone.utc).isoformat()
+
+    # Append if leader changed (or first entry)
+    if not history or history[-1].get("team") != leader:
+        history.append({"team": leader, "score": score, "timestamp": now})
+        history_path.write_text(json.dumps(history, indent=2) + "\n")
+
+    return history
+
+
+def _compute_time_at_top(history: list[dict]) -> dict[str, float]:
+    """Compute fraction of time each team has been the leader."""
+    if not history:
+        return {}
+
+    now = datetime.now(timezone.utc)
+    durations: dict[str, float] = {}
+
+    for i, entry in enumerate(history):
+        start = datetime.fromisoformat(entry["timestamp"])
+        if i + 1 < len(history):
+            end = datetime.fromisoformat(history[i + 1]["timestamp"])
+        else:
+            end = now
+        secs = max(0, (end - start).total_seconds())
+        durations[entry["team"]] = durations.get(entry["team"], 0) + secs
+
+    total = sum(durations.values())
+    if total == 0:
+        return {t: 1.0 for t in durations}  # single snapshot
+    return {t: d / total for t, d in durations.items()}
+
+
 def update_leaderboard(scores_dir: Path, output_path: Path) -> None:
     """Read all score files and produce a ranked leaderboard.json."""
     entries = []
@@ -194,6 +236,18 @@ def update_leaderboard(scores_dir: Path, output_path: Path) -> None:
         reverse=True,
     )
 
+    # Track time at top
+    history_path = output_path.parent / "top_history.json"
+    if entries:
+        history = _update_top_history(
+            history_path, entries[0]["team"], entries[0]["score"]
+        )
+        time_at_top = _compute_time_at_top(history)
+        for entry in entries:
+            entry["time_at_top"] = round(time_at_top.get(entry["team"], 0), 4)
+    else:
+        time_at_top = {}
+
     leaderboard = {
         "updated": datetime.now(timezone.utc).isoformat(),
         "entries": entries,

docs/index.html

@@ -25,6 +25,7 @@ <h1>ITm Seed Dataset Leaderboard</h1>
         <th class="hide-mobile">Size</th>
         <th>Seqs</th>
         <th>Fam</th>
+        <th class="hide-mobile">Top</th>
         <th>Commit</th>
       </tr>
     </thead>

docs/leaderboard.js

@@ -145,6 +145,12 @@
 
   // ── Detail panel builder ────────────────────────────────────────────
 
+  function formatTimeAtTop(frac) {
+    if (frac == null || frac === 0) return "";
+    const pct = (frac * 100).toFixed(0);
+    return `${scoreBar(frac * 100, 100)}${pct}%`;
+  }
+
   function buildRow(entry, rank) {
     const tr = document.createElement("tr");
     tr.innerHTML = `
@@ -157,6 +163,7 @@
       <td class="score-sub hide-mobile">${(entry.scores?.size ?? "").toString().slice(0, 4)}</td>
       <td class="count">${entry.n_sequences}</td>
       <td class="count">${entry.n_families}</td>
+      <td class="score-sub hide-mobile">${formatTimeAtTop(entry.time_at_top)}</td>
       <td class="score-sub"><code>${(entry.commit || "").slice(0, 7)}</code></td>
     `;
     return tr;
@@ -166,7 +173,7 @@
     const tr = document.createElement("tr");
     tr.className = "detail-row";
     const td = document.createElement("td");
-    td.colSpan = 10;
+    td.colSpan = 11;
 
     let checksHTML = "";
     if (teamData.checks) {
@@ -241,7 +248,7 @@
       data = await fetchJSON("leaderboard.json");
     } catch (e) {
       tbody.innerHTML =
-        '<tr><td colspan="10" class="empty-state">No leaderboard data yet. Submit an entry to get started.</td></tr>';
+        '<tr><td colspan="11" class="empty-state">No leaderboard data yet. Submit an entry to get started.</td></tr>';
       return;
     }
 
@@ -251,7 +258,7 @@
 
     if (!data.entries || data.entries.length === 0) {
       tbody.innerHTML =
-        '<tr><td colspan="10" class="empty-state">No entries yet.</td></tr>';
+        '<tr><td colspan="11" class="empty-state">No entries yet.</td></tr>';
       return;
     }
 

docs/leaderboard.json

@@ -1,19 +1,20 @@
 {
-  "updated": "2026-03-09T00:59:35.694353+00:00",
+  "updated": "2026-03-09T01:02:45.670618+00:00",
   "entries": [
     {
       "team": "test-entry",
       "score": 31.5,
       "n_sequences": 3,
       "n_families": 1,
-      "commit": "dffe4a1",
+      "commit": "26990c4",
       "scores": {
         "diversity": 0.0554,
         "annotation": 1.0,
         "functionality": 0.0167,
         "size": 0.2642,
         "total": 31.5
-      }
+      },
+      "time_at_top": 1.0
     }
   ]
 }

docs/scores/test-entry.json

@@ -1,7 +1,7 @@
 {
   "team": "test-entry",
-  "timestamp": "2026-03-09T00:46:07.291930+00:00",
-  "commit": "dffe4a1",
+  "timestamp": "2026-03-09T01:02:45.668555+00:00",
+  "commit": "26990c4",
   "n_sequences": 3,
   "n_families": 1,
   "checks": {

docs/top_history.json

@@ -0,0 +1,7 @@
+[
+  {
+    "team": "test-entry",
+    "score": 31.5,
+    "timestamp": "2026-03-09T01:02:45.670343+00:00"
+  }
+]

leaderboard.json

@@ -1,19 +1,20 @@
 {
-  "updated": "2026-03-09T00:59:35.694353+00:00",
+  "updated": "2026-03-09T01:02:45.670618+00:00",
   "entries": [
     {
       "team": "test-entry",
       "score": 31.5,
       "n_sequences": 3,
       "n_families": 1,
-      "commit": "dffe4a1",
+      "commit": "26990c4",
       "scores": {
         "diversity": 0.0554,
         "annotation": 1.0,
         "functionality": 0.0167,
         "size": 0.2642,
         "total": 31.5
-      }
+      },
+      "time_at_top": 1.0
     }
   ]
 }

scores/test-entry.json

@@ -1,7 +1,7 @@
 {
   "team": "test-entry",
-  "timestamp": "2026-03-09T00:46:07.291930+00:00",
-  "commit": "dffe4a1",
+  "timestamp": "2026-03-09T01:02:45.668555+00:00",
+  "commit": "26990c4",
   "n_sequences": 3,
   "n_families": 1,
   "checks": {