Update split_one_chevs balancemode v2

lib/teiserver/battle/balance/balance_types.ex

@@ -10,7 +10,8 @@ defmodule Teiserver.Battle.Balance.BalanceTypes do
           names: [String.t()],
           ranks: [non_neg_integer()],
           group_rating: rating_value(),
-          count: non_neg_integer()
+          count: non_neg_integer(),
+          uncertainties: [number()]
         }
 
   @type group() :: %{

lib/teiserver/battle/balance/cheeky_switcher_smart.ex

@@ -20,6 +20,7 @@ defmodule Teiserver.Battle.Balance.CheekySwitcherSmart do
   # Alias the types
   alias Teiserver.Battle.BalanceLib
   alias Teiserver.Battle.Balance.BalanceTypes, as: BT
+  import Teiserver.Helper.NumberHelper, only: [format: 1]
 
   # @type algorithm_state :: %{
   #   teams: map,
@@ -158,7 +159,7 @@ defmodule Teiserver.Battle.Balance.CheekySwitcherSmart do
             |> Enum.map(fn {group, _} ->
               group.names
               |> Enum.with_index()
-              |> Enum.map(fn {name, i} -> "#{name}[#{Enum.at(group.ratings, i)}]" end)
+              |> Enum.map(fn {name, i} -> "#{name}[#{format(Enum.at(group.ratings, i))}]" end)
             end)
             |> List.flatten()
             |> Enum.join(",")
@@ -168,7 +169,7 @@ defmodule Teiserver.Battle.Balance.CheekySwitcherSmart do
             |> Enum.map(fn {group, _} ->
               group.names
               |> Enum.with_index()
-              |> Enum.map(fn {name, i} -> "#{name}[#{Enum.at(group.ratings, i)}]" end)
+              |> Enum.map(fn {name, i} -> "#{name}[#{format(Enum.at(group.ratings, i))}]" end)
             end)
             |> List.flatten()
             |> Enum.join(",")
@@ -429,11 +430,11 @@ defmodule Teiserver.Battle.Balance.CheekySwitcherSmart do
 
     if next_group.count > 1 do
       [
-        "Group picked #{names |> Enum.join(", ")} for team #{team_key}, adding #{group_rating} points for a new total of #{round(existing_team_rating + group_rating)}"
+        "Group picked #{names |> Enum.join(", ")} for team #{team_key}, adding #{format(group_rating)} points for a new total of #{round(existing_team_rating + group_rating)}"
       ]
     else
       [
-        "Picked #{Enum.at(names, 0)} for team #{team_key}, adding #{group_rating} points for a new total of #{round(existing_team_rating + group_rating)}"
+        "Picked #{Enum.at(names, 0)} for team #{team_key}, adding #{format(group_rating)} points for a new total of #{round(existing_team_rating + group_rating)}"
       ]
     end
   end

lib/teiserver/battle/balance/split_one_chevs.ex

@@ -1,53 +1,104 @@
 defmodule Teiserver.Battle.Balance.SplitOneChevs do
   @moduledoc """
-    This balance algorithm first sorts the users by visible OS (match rating) descending. Then all rank=0 (one chevs) will be placed at the bottom of this sorted list.
+  Overview:
+  The goal of this algorithm is to mimic how a human would draft players given the visual information in a lobby.
+  Humans will generally avoid drafting overrated new players.
 
-    Next a team will be chosen to be the picking team. The picking team is the team with the least amount of players. If tied, then the team with the lowest total rating.
+  Details:
+  The team with the least amount of players will pick an unchosen player. If there are multiple teams tied for
+  the lowest player count, then the team with the lowest match rating picks.
 
-    Next the picking team will pick the player at the top of the sorted list.
+  Your team will prefer 3Chev+ players with high OS. If your team must pick a 1-2Chev player,
+  it will prefer lower uncertainty.
 
-    This is repeated until all players are chosen.
+  This is repeated until all players are chosen.
 
-    This algorithm completely ignores parties.
+  This algorithm completely ignores parties.
 
   """
   alias Teiserver.Battle.Balance.SplitOneChevsTypes, as: ST
   alias Teiserver.Battle.Balance.BalanceTypes, as: BT
+  import Teiserver.Helper.NumberHelper, only: [format: 1]
+
+  @splitter "---------------------------"
 
   @doc """
   Main entry point used by balance_lib
   See split_one_chevs_internal_test.exs for sample input
   """
   @spec perform([BT.expanded_group()], non_neg_integer(), list()) :: any()
-  def perform(expanded_group, team_count, _opts \\ []) do
-    members = flatten_members(expanded_group) |> sort_members()
-    %{teams: teams, logs: logs} = assign_teams(members, team_count)
-    standardise_result(teams, logs)
+  def perform(expanded_group, team_count, opts \\ []) do
+    if has_enough_noobs?(expanded_group) do
+      members = flatten_members(expanded_group) |> sort_members()
+      %{teams: teams, logs: logs} = assign_teams(members, team_count)
+      standardise_result(teams, logs)
+    else
+      # Not enough noobs; so call another balancer
+      result = Teiserver.Battle.Balance.LoserPicks.perform(expanded_group, team_count, opts)
+
+      new_logs =
+        ["Not enough new players; will use another balance algorithm.", @splitter, result.logs]
+        |> List.flatten()
+
+      Map.put(result, :logs, new_logs)
+    end
+  end
+
+  @doc """
+  For now this simply checks there is at least a single 1chev or a single 2chev.
+  However we could modify this in the future to be more complicated e.g. at least a single 1chev
+  or at least two, 2chevs.
+  """
+  @spec has_enough_noobs?([BT.expanded_group()]) :: bool()
+  def has_enough_noobs?(expanded_group) do
+    ranks =
+      Enum.map(expanded_group, fn x ->
+        Map.get(x, :ranks, [])
+      end)
+      |> List.flatten()
+
+    Enum.any?(ranks, fn x ->
+      x < 2
+    end)
   end
 
   @doc """
   Remove all groups/parties and treats everyone as solo players. This algorithm doesn't support parties.
   See split_one_chevs_internal_test.exs for sample input
   """
   def flatten_members(expanded_group) do
-    for %{members: members, ratings: ratings, ranks: ranks, names: names} <- expanded_group,
+    for %{
+          members: members,
+          ratings: ratings,
+          ranks: ranks,
+          names: names,
+          uncertainties: uncertainties
+        } <- expanded_group,
         # Zipping will create binary tuples from 2 lists
-        {id, rating, rank, name} <- Enum.zip([members, ratings, ranks, names]),
+        {id, rating, rank, name, uncertainty} <-
+          Enum.zip([members, ratings, ranks, names, uncertainties]),
         # Create result value
-        do: %{member_id: id, rating: rating, rank: rank, name: name}
+        do: %{
+          member_id: id,
+          rating: rating,
+          rank: rank,
+          name: name,
+          uncertainty: uncertainty
+        }
   end
 
   @doc """
-  Sorts members by rating but puts one chevs at the bottom
-  See split_one_chevs_internal_test.exs for sample input
+  Experienced players will be on top followed by noobs.
+  Experienced players are 3+ Chevs. They will be sorted with higher OS on top.
+  Noobs are 1-2 Chevs. They will be sorted with lower uncertainty on top.
   """
   def sort_members(members) do
-    non_noobs = Enum.filter(members, fn x -> x.rank != 0 end)
-    noobs = Enum.filter(members, fn x -> x.rank == 0 end)
+    non_noobs = Enum.filter(members, fn x -> x.rank >= 2 end)
+    noobs = Enum.filter(members, fn x -> x.rank < 2 end)
 
     [
       Enum.sort_by(non_noobs, fn x -> x.rating end, &>=/2),
-      Enum.sort_by(noobs, fn x -> x.rating end, &>=/2)
+      Enum.sort_by(noobs, fn x -> x.uncertainty end, &<=/2)
     ]
     |> List.flatten()
   end
@@ -59,14 +110,21 @@ defmodule Teiserver.Battle.Balance.SplitOneChevs do
   def assign_teams(member_list, number_of_teams) do
     default_acc = %{
       teams: create_empty_teams(number_of_teams),
-      logs: ["Begin split_one_chevs balance"]
+      logs: [
+        "Algorithm: split_one_chevs",
+        @splitter,
+        "Your team will try and pick 3Chev+ players first, with preference for higher OS. If 1-2Chevs are the only remaining players, then lower uncertainty is preferred.",
+        @splitter
+      ]
     }
 
     Enum.reduce(member_list, default_acc, fn x, acc ->
       picking_team = get_picking_team(acc.teams)
       update_picking_team = Map.merge(picking_team, %{members: [x | picking_team.members]})
       username = x.name
-      new_log = "#{username} (Chev: #{x.rank + 1}) picked for Team #{picking_team.team_id}"
+
+      new_log =
+        "#{username} (#{format(x.rating)}, σ: #{format(x.uncertainty)}, Chev: #{x.rank + 1}) picked for Team #{picking_team.team_id}"
 
       %{
         teams: [update_picking_team | get_non_picking_teams(acc.teams, picking_team)],