Add new rating system setup task

lib/teiserver/battle/libs/balance_lib.ex

@@ -583,8 +583,8 @@ defmodule Teiserver.Battle.BalanceLib do
     captain.member_id
   end
 
-  @spec default_rating :: List.t()
-  @spec default_rating(non_neg_integer()) :: List.t()
+  @spec default_rating :: any()
+  @spec default_rating(non_neg_integer()) :: any()
   def default_rating(rating_type_id \\ nil) do
     {skill, uncertainty} = Openskill.rating()
     rating_value = calculate_rating_value(skill, uncertainty)
@@ -595,7 +595,8 @@ defmodule Teiserver.Battle.BalanceLib do
       skill: skill,
       uncertainty: uncertainty,
       rating_value: rating_value,
-      leaderboard_rating: leaderboard_rating
+      leaderboard_rating: leaderboard_rating,
+      num_matches: 0
     }
   end
 
@@ -704,7 +705,24 @@ defmodule Teiserver.Battle.BalanceLib do
 
   @spec calculate_rating_value(float(), float()) :: float()
   def calculate_rating_value(skill, uncertainty) do
-    max(skill - uncertainty, 0)
+    calculate_rating_value(skill, uncertainty, 0)
+  end
+
+  @spec calculate_rating_value(float(), float(), integer()) :: float()
+  def calculate_rating_value(skill, uncertainty, num_matches) do
+    config = Config.get_site_config_cache("hidden.Rating method")
+
+    if config == "start at zero; converge to skill" do
+      num_matches_target = get_num_matches_for_rating_to_equal_skill()
+
+      min(1, num_matches / num_matches_target) * skill
+    else
+      max(skill - uncertainty, 0)
+    end
+  end
+
+  def get_num_matches_for_rating_to_equal_skill() do
+    Config.get_site_config_cache("profile.Num matches for rating to equal skill")
   end
 
   @doc """

lib/teiserver/game/libs/match_rating_lib.ex

@@ -467,7 +467,10 @@ defmodule Teiserver.Game.MatchRatingLib do
 
     rating_type_id = user_rating.rating_type_id
     {new_skill, new_uncertainty} = rating_update
-    new_rating_value = BalanceLib.calculate_rating_value(new_skill, new_uncertainty)
+
+    new_rating_value =
+      BalanceLib.calculate_rating_value(new_skill, new_uncertainty, new_num_matches)
+
     new_leaderboard_rating = BalanceLib.calculate_leaderboard_rating(new_skill, new_uncertainty)
 
     Account.update_rating(user_rating, %{

lib/teiserver/libs/teiserver_configs.ex

@@ -13,6 +13,7 @@ defmodule Teiserver.TeiserverConfigs do
     lobby_configs()
     debugging_configs()
     profile_configs()
+    hidden_configs()
   end
 
   @spec site_configs :: any
@@ -578,6 +579,15 @@ defmodule Teiserver.TeiserverConfigs do
       opts: [choices: ["Leaderboard rating", "Rating value", "Playtime", "Role"]]
     })
 
+    add_site_config_type(%{
+      key: "profile.Num matches for rating to equal skill",
+      section: "Profiles",
+      type: "integer",
+      default: 30,
+      permissions: ["Admin"],
+      description: "The minimum number of matches required for match rating to equal skill"
+    })
+
     add_site_config_type(%{
       key: "user.Enable one time links",
       section: "User permissions",
@@ -633,4 +643,18 @@ defmodule Teiserver.TeiserverConfigs do
       value_label: "Light mode as default"
     })
   end
+
+  # These configs can be saved to the database but will not be editable on the Admin page
+  @spec hidden_configs() :: :ok
+  defp hidden_configs() do
+    add_site_config_type(%{
+      key: "hidden.Rating method",
+      section: "Hidden",
+      type: "select",
+      default: "skill minus uncertainty",
+      permissions: ["Admin"],
+      description: "The rating system. Use Mix.Tasks.Teiserver.ProvisionalRatingSetup to change.",
+      opts: [choices: ["skill minus uncertainty", "start at zero; converge to skill"]]
+    })
+  end
 end

lib/teiserver/mix_tasks/provisional_rating_setup.ex

@@ -0,0 +1,112 @@
+defmodule Mix.Tasks.Teiserver.ProvisionalRatingSetup do
+  @moduledoc """
+  Running this task will change the rating system to one where new players start at zero,
+  then converge towards their skill over time.
+  The rating formula:
+  least(1, num_matches/30) * skill
+  30 is the target number of matches for your rating to just equal to skill.
+  This number is adjustable on the admin site config page.
+
+  To use this new rating system run:
+  mix teiserver.provisional_rating_setup
+
+  To rollback use:
+  mix teiserver.provisional_rating_setup -rollback
+  """
+
+  use Mix.Task
+  require Logger
+  alias Teiserver.Config
+  alias Teiserver.Battle.BalanceLib
+
+  def run(args) do
+    Application.ensure_all_started(:teiserver)
+
+    rollback? = Enum.member?(args, "-rollback")
+    target_matches = BalanceLib.get_num_matches_for_rating_to_equal_skill()
+
+    sql_transaction_result =
+      Ecto.Multi.new()
+      |> Ecto.Multi.run(:create_temp_table, fn repo, _ ->
+        {query, params} =
+          case rollback? do
+            false ->
+              {"""
+               CREATE temp table temp_table as
+               SELECT
+                 *,
+                 least(1, cast(num_matches as decimal) / $1) * skill as new_rating
+               FROM
+                 teiserver_account_ratings tar;
+               """, [target_matches]}
+
+            true ->
+              {"""
+               CREATE temp table temp_table as
+               SELECT
+                 *,
+                 greatest(0,skill-uncertainty ) as new_rating
+               FROM
+                 teiserver_account_ratings tar;
+               """, []}
+          end
+
+        Ecto.Adapters.SQL.query(repo, query, params)
+      end)
+      |> Ecto.Multi.run(:add_logs, fn repo, _ ->
+        query = """
+           INSERT INTO teiserver_game_rating_logs (inserted_at, rating_type_id, user_id, value)
+        SELECT
+        now(),
+        rating_type_id,
+        user_id,
+        JSON_BUILD_OBJECT(
+          'skill', skill,
+          'reason', 'New rating system',
+          'uncertainty', uncertainty,
+          'rating_value', new_rating,
+          'skill_change', 0.0,
+          'uncertainty_change', 0.0,
+          'rating_value_change', t.new_rating - t.rating_value,
+          'num_matches', num_matches
+        )
+        FROM temp_table t;
+        """
+
+        Ecto.Adapters.SQL.query(repo, query, [])
+      end)
+      |> Ecto.Multi.run(:update_ratings, fn repo, _ ->
+        query = """
+        UPDATE teiserver_account_ratings tar
+        SET
+          rating_value = t.new_rating,
+          last_updated = now()
+         FROM temp_table t
+        WHERE t.user_id = tar.user_id
+          and t.rating_type_id = tar.rating_type_id;
+
+        """
+
+        Ecto.Adapters.SQL.query(repo, query, [])
+      end)
+      |> Teiserver.Repo.transaction()
+
+    with {:ok, _result} <- sql_transaction_result do
+      case rollback? do
+        true ->
+          Logger.info("Rollback to old rating system complete")
+
+          # This config is not viewable in the admin page as we don't want someone to manually change it.
+          # To change it use this mix task
+          Config.update_site_config("hidden.Rating method", "skill minus uncertainty")
+
+        false ->
+          Logger.info("New rating system change complete")
+          Config.update_site_config("hidden.Rating method", "start at zero; converge to skill")
+      end
+    else
+      _ ->
+        Logger.error("Task failed.")
+    end
+  end
+end

lib/teiserver_web/controllers/admin/site_config_controller.ex

@@ -19,7 +19,14 @@ defmodule TeiserverWeb.Admin.SiteConfigController do
 
   @spec index(Plug.Conn.t(), any) :: Plug.Conn.t()
   def index(conn, _params) do
-    site_configs = Config.get_grouped_site_configs()
+    site_configs =
+      Config.get_grouped_site_configs()
+      |> Enum.filter(fn x ->
+        case x do
+          {"Hidden", _} -> false
+          _ -> true
+        end
+      end)
 
     conn
     |> assign(:site_configs, site_configs)

lib/teiserver_web/controllers/admin/user_controller.ex

@@ -514,7 +514,13 @@ defmodule TeiserverWeb.Admin.UserController do
             user_rating = existing_rating || BalanceLib.default_rating()
             new_skill = changes["skill"] |> float_parse
             new_uncertainty = changes["uncertainty"] |> float_parse
-            new_rating_value = BalanceLib.calculate_rating_value(new_skill, new_uncertainty)
+
+            new_rating_value =
+              BalanceLib.calculate_rating_value(
+                new_skill,
+                new_uncertainty,
+                user_rating.num_matches
+              )
 
             new_leaderboard_rating =
               BalanceLib.calculate_leaderboard_rating(new_skill, new_uncertainty)

test/teiserver/game/libs/match_rating_lib_test.exs

@@ -7,6 +7,7 @@ defmodule Teiserver.Game.MatchRatingLibTest do
   alias Teiserver.Account
   alias Teiserver.Battle
   alias Teiserver.Game
+  alias Teiserver.Config
 
   test "num_matches is updated after rating a match" do
     # Create two user
@@ -65,6 +66,105 @@ defmodule Teiserver.Game.MatchRatingLibTest do
     assert ratings[user1.id].num_matches == 2
   end
 
+  describe "Test rating system where new players start at zero" do
+    test "rating after one match" do
+      # Set config to use provisional ratings
+      Config.update_site_config("hidden.Rating method", "start at zero; converge to skill")
+
+      # Create two user
+      user1 = AccountTestLib.user_fixture()
+      user2 = AccountTestLib.user_fixture()
+
+      match = create_fake_match(user1.id, user2.id)
+
+      MatchRatingLib.rate_match(match.id)
+      rating_type_id = Game.get_or_add_rating_type(match.game_type)
+
+      # Check ratings of users after match
+      ratings = get_ratings([user1.id, user2.id], rating_type_id)
+
+      assert ratings[user1.id].skill == 27.637760127073694
+      assert ratings[user2.id].skill == 22.362239872926306
+
+      # New players start at zero then converge to skill over time
+      assert ratings[user1.id].rating_value == 0.9212586709024565
+      assert ratings[user2.id].rating_value == 0.7454079957642102
+    end
+
+    test "rating after many matches" do
+      # Set config to use provisional ratings
+      Config.update_site_config("hidden.Rating method", "start at zero; converge to skill")
+
+      # Create two user
+      user1 = AccountTestLib.user_fixture()
+      user2 = AccountTestLib.user_fixture()
+
+      matches_target =
+        Config.get_site_config_cache("profile.Num matches for rating to equal skill")
+
+      match_ids = 1..matches_target
+
+      matches =
+        Enum.map(match_ids, fn x ->
+          match = create_fake_match(user1.id, user2.id)
+
+          MatchRatingLib.rate_match(match.id)
+
+          match
+        end)
+
+      rating_type_id = Game.get_or_add_rating_type(Enum.at(matches, 0).game_type)
+
+      # Check ratings of users after match
+      ratings = get_ratings([user1.id, user2.id], rating_type_id)
+
+      assert ratings[user1.id].skill == 41.851075350620384
+      assert ratings[user2.id].skill == 8.148924649379609
+
+      # Rating should equal skill
+      assert ratings[user1.id].rating_value == ratings[user1.id].skill
+      assert ratings[user2.id].rating_value == ratings[user2.id].skill
+
+      # Rate one more match and rating should still equal skill since we've hit the matches_target
+      match = create_fake_match(user1.id, user2.id)
+      MatchRatingLib.rate_match(match.id)
+      # Check ratings of users after match
+      ratings = get_ratings([user1.id, user2.id], rating_type_id)
+
+      # Rating should equal skill
+      assert ratings[user1.id].rating_value == ratings[user1.id].skill
+      assert ratings[user2.id].rating_value == ratings[user2.id].skill
+    end
+  end
+
+  describe "Test rating system where rating = skill minus uncertainty" do
+    test "rating after one match" do
+      # Set config to use provisional ratings
+      Config.update_site_config("hidden.Rating method", "skill minus uncertainty")
+
+      # Create two user
+      user1 = AccountTestLib.user_fixture()
+      user2 = AccountTestLib.user_fixture()
+
+      match = create_fake_match(user1.id, user2.id)
+
+      MatchRatingLib.rate_match(match.id)
+      rating_type_id = Game.get_or_add_rating_type(match.game_type)
+
+      # Check ratings of users after match
+      ratings = get_ratings([user1.id, user2.id], rating_type_id)
+
+      assert ratings[user1.id].skill == 27.637760127073694
+      assert ratings[user2.id].skill == 22.362239872926306
+
+      assert ratings[user1.id].rating_value ==
+               ratings[user1.id].skill - ratings[user1.id].uncertainty
+
+      assert ratings[user2.id].rating_value ==
+               ratings[user2.id].skill - ratings[user2.id].uncertainty
+    end
+  end
+
   defp get_ratings(userids, rating_type_id) do
     Account.list_ratings(
       search: [