Guessing functionality; should i use shallow nesting?

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I’m trying to add guessing functionality to the Flashcards App.

The way i see it, a guess is taken on a particular card, so a guess belongs_to a card, and a card has_many guesses. So far so good, but when it comes to routing i’ve read that Resources should never be nested more than 1 level deep and that a way to avoid deep nesting is using shallow nesting, i.e. only generate collection actions scoped under the parent.

So now i have the following in my routes.rb file

resources :decks do
   resources :cards, except: :index do
      resources :guesses, only: [:new, :create]
   end
end

resources :guesses, only: :show

and my GuessesController looks like this:

class GuessesController < ApplicationController
 before_filter :authenticate

 def show
   @guess = find_guess
   unless @guess.belongs_to_user? current_user
     redirect_to decks_path
   end
   @card = @guess.card
   @deck = @card.deck
 end

 def new
   @deck = find_deck
   @card = find_card
   @guess = @card.guesses.new
 end
 
 def create
   @deck = find_deck
   @card = find_card
   @guess = @card.guesses.new(params[:guess])
   @guess.save
   redirect_to @guess
 end
    
 def find_deck
   current_user.decks.find(params[:deck_id])
 end
    
 def find_card
   @deck.cards.find(params[:card_id])
 end
    
 def find_guess
   guess = Guess.find(params[:id])
 end
   
end

Which seems to work fine, but since the show action is not being accessed through deck and card (route is simply /guesses/:id) i have to check to make sure that the user isn’t trying to access guesses that don’t belong to him.

My question is, am i going about this the right way? Is there a better approach? Should i simply deep nest my routes?

Thanks in advance