diff --git a/app/services/discourse_rewind/rewind/action/fbff.rb b/app/services/discourse_rewind/rewind/action/fbff.rb
new file mode 100644
index 0000000..226e174
--- /dev/null
+++ b/app/services/discourse_rewind/rewind/action/fbff.rb
@@ -0,0 +1,104 @@
+# frozen_string_literal: true
+
+# Forum Best Friend Forever ranking
+# Score is informative only, do not show in UI
+module DiscourseRewind
+  class Rewind::Action::Fbff < Action::Base
+    MAX_SUMMARY_RESULTS = 50
+    LIKE_SCORE = 1
+    REPLY_SCORE = 10
+
+    def call
+      most_liked_users =
+        like_query(date)
+          .where(acting_user_id: user.id)
+          .group(:user_id)
+          .order("COUNT(*) DESC")
+          .limit(MAX_SUMMARY_RESULTS)
+          .pluck("user_actions.user_id, COUNT(*)")
+          .map { |user_id, count| { user_id => count } }
+          .reduce({}, :merge)
+
+      most_liked_by_users =
+        like_query(date)
+          .where(user: user)
+          .group(:acting_user_id)
+          .order("COUNT(*) DESC")
+          .limit(MAX_SUMMARY_RESULTS)
+          .pluck("acting_user_id, COUNT(*)")
+          .map { |acting_user_id, count| { acting_user_id => count } }
+          .reduce({}, :merge)
+
+      users_who_most_replied_me =
+        post_query(user, date)
+          .where(posts: { user_id: user.id })
+          .group("replies.user_id")
+          .order("COUNT(*) DESC")
+          .limit(MAX_SUMMARY_RESULTS)
+          .pluck("replies.user_id, COUNT(*)")
+          .map { |user_id, count| { user_id => count } }
+          .reduce({}, :merge)
+
+      users_i_most_replied =
+        post_query(user, date)
+          .where("replies.user_id = ?", user.id)
+          .group("posts.user_id")
+          .order("COUNT(*) DESC")
+          .limit(MAX_SUMMARY_RESULTS)
+          .pluck("posts.user_id, COUNT(*)")
+          .map { |user_id, count| { user_id => count } }
+          .reduce({}, :merge)
+
+      #TODO include chat?
+
+      fbffs = [
+        apply_score(most_liked_users, LIKE_SCORE),
+        apply_score(most_liked_by_users, LIKE_SCORE),
+        apply_score(users_who_most_replied_me, REPLY_SCORE),
+        apply_score(users_i_most_replied, REPLY_SCORE),
+      ]
+
+      fbffs =
+        fbffs
+          .flatten
+          .inject { |h1, h2| h1.merge(h2) { |_, v1, v2| v1 + v2 } }
+          .sort_by { |_, v| -v }
+          .first(6)
+          .to_h
+
+      { data: fbffs, identifier: "fbff" }
+    end
+
+    def post_query(user, date)
+      Post
+        .joins(:topic)
+        .includes(:topic)
+        .where(
+          "posts.post_type IN (?)",
+          Topic.visible_post_types(user.guardian, include_moderator_actions: false),
+        )
+        .joins(
+          "INNER JOIN posts replies ON posts.topic_id = replies.topic_id AND posts.reply_to_post_number = replies.post_number",
+        )
+        .joins(
+          "INNER JOIN topics ON replies.topic_id = topics.id AND topics.archetype <> 'private_message'",
+        )
+        .joins(
+          "AND replies.post_type IN (#{Topic.visible_post_types(user, include_moderator_actions: false).join(",")})",
+        )
+        .where("replies.created_at BETWEEN ? AND ?", date.first, date.last)
+        .where("replies.user_id <> posts.user_id")
+    end
+
+    def like_query(date)
+      UserAction
+        .joins(:target_topic, :target_post)
+        .where(created_at: date)
+        .where(action_type: UserAction::WAS_LIKED)
+    end
+
+    def apply_score(users, score)
+      users.map { |user_id, count| { user_id => count * score } }
+    end
+  end
+end