class method on Player to return player with best average game score

  5   def self.top_player
  6     averages = {}
  7     joins(:games).group(:id).each {|player| averages[player.name.to_sym] = player.games.average(:score).to_i}                                               
  8     averages.max_by{|k,v| v}[0]
  9   end

console

irb(main):019:0> Player.joins(:games).group(:id).select('*, AVG(games.score) AS average_score')
  Player Load (0.3ms)  SELECT *, AVG(games.score) AS average_score FROM "players" INNER JOIN "games" ON "games"."player_id" = "players"."id" GROUP BY "players"."id"
[
    [0] #<Player:0x007f8c94ec8e20> {
                :id => 4,
              :name => "asdffd",
        :created_at => Mon, 13 Jun 2016 16:13:41 UTC +00:00,
        :updated_at => Mon, 13 Jun 2016 16:13:41 UTC +00:00
    },
    [1] #<Player:0x007f8c94ec8b28> {
                :id => 6,
              :name => "fsdfdsf",
        :created_at => Mon, 13 Jun 2016 16:14:27 UTC +00:00,
        :updated_at => Mon, 13 Jun 2016 16:14:27 UTC +00:00
    },
    [2] #<Player:0x007f8c94ec8808> {
                :id => 8,
              :name => "fdsfasdf",
        :created_at => Mon, 13 Jun 2016 16:14:48 UTC +00:00,
        :updated_at => Mon, 13 Jun 2016 16:14:48 UTC +00:00
    }
]