class Array
  def sum
    reduce(0, :+)
  end

  def avg
    sum.fdiv(size)
  end
end

def sr_diff
  sr = (18..23).to_a.sample

  if win?
    sr
  else
    sr * -1
  end
end

def win_rate
  0.52
end

def win?
  percent = (win_rate * 100).round
  dice_roll = (0..100).to_a.sample
  dice_roll <= percent
end

def games_to_play_to_reach(goal:, start:)
  sr = start
  games_played = 0

  loop do
    games_played += 1
    sr += sr_diff
    break if sr >= goal
  end

  games_played
end

goal = 2600
start = 2300

number_of_games_played = 1_000.times.map do
  games_to_play_to_reach(goal: goal, start: start)
end

games = number_of_games_played.avg.round

puts "You should expect to play #{games} games to each #{goal} SR, starting from #{start} with a winrate of #{(win_rate*100).round}%"