diff --git a/app/services/tournament_services/tournament_backup_service.rb b/app/services/tournament_services/tournament_backup_service.rb
index d189c27..cd678e0 100644
--- a/app/services/tournament_services/tournament_backup_service.rb
+++ b/app/services/tournament_services/tournament_backup_service.rb
@@ -41,7 +41,11 @@ class TournamentBackupService
         mat_assignment_rules: @tournament.mat_assignment_rules.map do |rule|
           rule.attributes.merge(
             mat: Mat.find_by(id: rule.mat_id)&.attributes.slice("name"),
-            weight_classes: rule.weight_classes.map do |weight_id|
+            # Emit the human-readable max values under a distinct key to avoid
+            # colliding with the raw DB-backed "weight_classes" attribute (which
+            # is stored as a comma-separated string). Using a different key
+            # prevents duplicate JSON keys when symbols and strings are both present.
+            "weight_class_maxes" => rule.weight_classes.map do |weight_id|
               Weight.find_by(id: weight_id)&.max
             end
           )
diff --git a/app/services/tournament_services/wrestlingdev_importer.rb b/app/services/tournament_services/wrestlingdev_importer.rb
index 2c18440..91d4caf 100644
--- a/app/services/tournament_services/wrestlingdev_importer.rb
+++ b/app/services/tournament_services/wrestlingdev_importer.rb
@@ -86,17 +86,30 @@ class WrestlingdevImporter
     mat_assignment_rules.each do |rule_attributes|
       mat_name = rule_attributes.dig("mat", "name")
       mat = Mat.find_by(name: mat_name, tournament_id: @tournament.id)
-
-      # Map max values of weight_classes to their new IDs
-      new_weight_classes = rule_attributes["weight_classes"].map do |max_value|
-        Weight.find_by(max: max_value, tournament_id: @tournament.id)&.id
-      end.compact
-
-      # Extract bracket_positions and rounds
+  
+      # Prefer the new "weight_class_maxes" key emitted by backups (human-readable
+      # max values). If not present, fall back to the legacy "weight_classes"
+      # value which may be a comma-separated string or an array of IDs.
+      if rule_attributes.key?("weight_class_maxes") && rule_attributes["weight_class_maxes"].respond_to?(:map)
+        new_weight_classes = rule_attributes["weight_class_maxes"].map do |max_value|
+          Weight.find_by(max: max_value, tournament_id: @tournament.id)&.id
+        end.compact
+      elsif rule_attributes["weight_classes"].is_a?(Array)
+        # Already an array of IDs
+        new_weight_classes = rule_attributes["weight_classes"].map(&:to_i)
+      elsif rule_attributes["weight_classes"].is_a?(String)
+        # Comma-separated IDs stored in the DB column; split into integers.
+        new_weight_classes = rule_attributes["weight_classes"].to_s.split(",").map(&:strip).reject(&:empty?).map(&:to_i)
+      else
+        new_weight_classes = []
+      end
+  
+      # Extract bracket_positions and rounds (leave as-is; model will coerce if needed)
       bracket_positions = rule_attributes["bracket_positions"]
       rounds = rule_attributes["rounds"]
-
-      rule_attributes.except!("id", "mat", "tournament_id", "weight_classes")
+  
+      # Remove any keys we don't want to mass-assign (including both old/new weight keys)
+      rule_attributes.except!("id", "mat", "tournament_id", "weight_classes", "weight_class_maxes")
       
       MatAssignmentRule.create(
         rule_attributes.merge(