template_alphabeta.rb

  def alphabeta(board, player, depth, alpha, beta)
    board.open_cells.each_key do |cell|
      board.add_marker(player.opponent.marker, cell)
      score = (apply_minimax(board, player.opponent, cell, depth += 1, alpha, beta) / depth.to_f)
      alpha = player.get_alpha(alpha, score)
      beta = player.get_beta(beta, score)
      board.remove_marker(cell)
      break if alpha >= beta
    end
    player.return_value(alpha, beta)
  end