diff --git a/db/migrate/20240626181338_reindex_p_at10_code.rb b/db/migrate/20240626181338_reindex_p_at10_code.rb
new file mode 100644
index 000000000..b7bf0bba9
--- /dev/null
+++ b/db/migrate/20240626181338_reindex_p_at10_code.rb
@@ -0,0 +1,12 @@
+class ReindexPAt10Code < ActiveRecord::Migration[7.1]
+  # force existing P@10 scorers to reload using the latest scorer information.
+  def change
+    scorers_to_update = ['P@10']
+    scorers_to_update.each do |scorer_name|
+      scorer = Scorer.where(name: scorer_name, communal: true).first
+      name = scorer.name
+      scorer.code = File.readlines("./db/scorers/#{name.downcase}.js",'\n').join('\n')
+      scorer.save!
+    end    
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 0a19e24b7..116dc63f7 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2024_06_26_173902) do
+ActiveRecord::Schema[7.1].define(version: 2024_06_26_181338) do
   create_table "active_storage_attachments", charset: "utf8mb4", collation: "utf8mb4_bin", force: :cascade do |t|
     t.string "name", null: false
     t.string "record_type", null: false
diff --git a/db/scorers/p@10.js b/db/scorers/p@10.js
index e8a37cbc4..f094fbdb8 100644
--- a/db/scorers/p@10.js
+++ b/db/scorers/p@10.js
@@ -1,4 +1,11 @@
-var k = 10 // @Rank
-var score = avgRating(k);
-
+const k = 10; // @Rank
+// k may be > length list, so count up the total number of documents processed.
+let count = 0, total = 0;
+eachDoc(function(doc, i) {
+    if (hasDocRating(i) && (docRating(i)) > 0) { // map 0 -> irrel, 1+ ->rel
+        count = count + 1;
+    }
+    total = total + 1.0;
+}, k);
+const score = total ? count / total : 0.0;
 setScore(score);