That’s not really cheating if you ask me… there are no points awarded for how you memorize the deck of card. However, when it comes to competitions it’s a little different.
That is not entirely true, because that all depends on how fast you can memorize a deck of cards. Say that it takes you 2-3 minutes… which is definitely achievable whilst still far from what better competitors will do. If you can’t do a whole deck in under 5 minutes, it’s like @Simon says (…finally got the Simon says joke in )
Yes, the last couple of cards go into working memory, but that is only so you can stop the timer that little bit earlier. Afterwards, you form an image for those last couple of cards as well. Bear in mind that you can’t just start recall before the 5 minutes for memorization are up, so…
…that is not really an option. But what you’d do in the remaining time is exactly that… run backwards in your head… skip the difficult ones, re-run forward. backward again. Make sure you got what you got and start working on the difficult ones.
Usually, you’ll keep a couple of blanks, but once you do the recall and put everything that you know down… the limited number of cards you still hold in your hand are easily checked by just going through all the different possible combinations… just see if (in case of PAO) you remember any of the cards being a P in one of the missing locations; see if you can remember a card as an object in a location, etc.