@@ -172,25 +172,29 @@ def entry(report, name)
     report["entries"].find { |e| e["name"] == name }
   end
 
-  # Per report: [i/s, error, relative to the reference's median]. Relative is nil for a suspect or zero result, or a report the reference does not have.
+  # Per report: [i/s, error, relative to the reference's median of the claimed report].
+  # Every report of a benchmark shares that one baseline, so on the chart the higher line is the faster report.
+  # Relative is nil for a suspect or zero result, or when the reference has no usable pass of the claimed report.
   def cross_run(report, names, ref_ips)
     entries = names.each_with_index.map do |name, i|
       e = entry(report, name) or next nil
-      rel = ref_ips[i].empty? || !e["ips"].positive? || e["ips"] > SUSPECT_IPS ? nil : (e["ips"] / median(ref_ips[i])).round(4)
+      rel = ref_ips[0].empty? || !e["ips"].positive? || e["ips"] > SUSPECT_IPS ? nil : (e["ips"] / median(ref_ips[0])).round(4)
       [e["ips"].round(3), e["error"].to_f.round(1), rel]
     end
     { entries: entries, pass: report["pass"] }
   end
 
-  # The reference itself: its median pass, 1.0 relative to itself.
+  # The reference itself: its median pass, relative to its own claimed report (1.0 for the claimed report).
   def reference_run(passes, names, ref_ips)
     entries = names.each_with_index.map do |name, i|
       es = passes.filter_map { |r| entry(r, name) }
       next nil if es.empty?
 
       usable = es.select { |e| e["ips"].positive? && e["ips"] <= SUSPECT_IPS }
       pick = usable.empty? ? es : usable
-      [median(pick.map { |e| e["ips"] }).round(3), median(pick.map { |e| e["error"].to_f }).round(1), ref_ips[i].empty? ? nil : 1.0]
+      ips = median(pick.map { |e| e["ips"] })
+      rel = ref_ips[0].empty? || ref_ips[i].empty? ? nil : (median(ref_ips[i]) / median(ref_ips[0])).round(4)
+      [ips.round(3), median(pick.map { |e| e["error"].to_f }).round(1), rel]
     end
     { entries: entries, passes: passes.map { |r| r["pass"] }.sort }
   end
 
@@ -609,7 +609,7 @@ <h2 class="bh">FastRuby<span>.io</span> keeps fast-ruby running</h2>
 })();
 </script>
 <script>
-// Across Rubies. Each entry is [i/s, error, relative to the reference's median].
+// Across Rubies. Each entry is [i/s, error, relative to the reference's median of the claimed report].
 (function () {
   const $ = (id) => document.getElementById(id);
   const D = window.ACROSS_RUBIES;
@@ -634,7 +634,7 @@ <h2 class="bh">FastRuby<span>.io</span> keeps fast-ruby running</h2>
   const sus = (e) => !!e && e[0] > M.suspect;
   // A result that can be drawn and compared: it ran and is not suspect.
   const ok = (e) => !!e && !sus(e) && e[0] > 0;
-  // Relative needs the reference to have that report.
+  // Relative needs the reference to have the claimed report.
   const val = (e) => ok(e) ? (showing === "rel" ? e[2] : e[0]) : null;
   // Two reports of one build, measured seconds apart: same-ish when the error bars overlap, as benchmark-ips says.
   const same = (a, b) => a[0] + a[1] > b[0] - b[1] && a[0] - a[1] < b[0] + b[1];
@@ -824,7 +824,10 @@ <h2 class="bh">FastRuby<span>.io</span> keeps fast-ruby running</h2>
     if (mode && !has(mode)) mode = "";
     $("rmodes").innerHTML = MODES.map(([m, name]) => `<button type="button" class="chip" data-m="${m}" aria-pressed="${m === mode}" ${has(m) ? "" : 'disabled title="Not built in this run"'}>${name}</button>`).join("");
     $("rshow").innerHTML = SHOWS.map(([k, name]) => `<button type="button" class="chip" data-s="${k}" aria-pressed="${k === showing}">${esc(name)}</button>`).join("");
-    $("rhint").textContent = mode ? "Dashed: the same Rubies without the JIT, on the same machine." : "";
+    const hints = [];
+    if (showing === "rel") hints.push(`1× is the claimed idiom on ${nice(REF)}.`);
+    if (mode) hints.push("Dashed: the same Rubies without the JIT, on the same machine.");
+    $("rhint").textContent = hints.join(" ");
     let h = "", sec = null;
     B.forEach((b, n) => {
       if (b.section !== sec) { sec = b.section; h += `<h2>${esc(sec)}<span class="on">${esc(MODES.find(([m]) => m === mode)[1])}</span></h2>`; }