Add probabilities to Dyeworks items in Item Getting Guide

I'm gonna better explain the gacha nature, I'm doing this part first!

app/helpers/items_helper.rb

@@ -240,6 +240,17 @@ module ItemsHelper
     {nc_total:, summary:}
   end
 
+  def probability(p)
+    case p
+    when 1
+      "100%"
+    when 0
+      "0%"
+    else
+      "#{p.numerator} in #{p.denominator}"
+    end
+  end
+
   private
 
   def build_on_pet_types(species, special_color=nil, &block)

app/models/item.rb

@@ -17,6 +17,8 @@ class Item < ApplicationRecord
   has_many :swf_assets, :through => :parent_swf_asset_relationships
   belongs_to :dyeworks_base_item, class_name: "Item",
     default: -> { inferred_dyeworks_base_item }, optional: true
+  has_many :dyeworks_variants, class_name: "Item",
+    inverse_of: :dyeworks_base_item
 
 
   attr_writer :current_body_id, :owned, :wanted

app/models/item/dyeworks.rb

@@ -83,6 +83,16 @@ class Item
 			date
 		end
 
+		# The probability of getting this item when dyeing the base item.
+		def dyeworks_odds
+			return nil unless dyeworks?
+
+			num_variants = dyeworks_base_item.dyeworks_variants.count
+			raise "Item's Dyeworks base has *no* variants??" if num_variants < 1
+
+			Rational(1, num_variants)
+		end
+
 		# Infer what base item this Dyeworks item probably relates to, based on
 		# their names. We only use this when a new item is modeled to initialize
 		# the `dyeworks_base_item` relationship in the database; after that, we

app/views/items/sources.html.haml

@@ -70,8 +70,8 @@
 					- base_item = item.dyeworks_base_item
 
 					- content_for :subtitle, flush: true do
-						= link_to base_item.name, base_item, target: "_blank"
-						+ 1 potion
+						#{link_to base_item.name, base_item, target: "_blank"},
+						#{probability item.dyeworks_odds} chance
 						- if item.dyeworks_permanent?
 							%span.dyeworks-timeframe{
 								title: "This recipe is NOT currently scheduled to be removed " +