Here is an idea from the legenday Moe Seidenstein. It is a principle as well as a trick…
Have a spectator shuffle the deck. Then have them remove any 4 of a kind. Now riffle the cards in front of your face. As they riffle by – quickly ask yourself if you see any Aces, Twos, Threes, Fours, Fives, Sixes, Sevens, Eights, Nines, Tens, Jacks, Queens, Kings. It might sound strange – but your ‘kinetic’ memory will notice which card value was not seen. [This may seem impossible – but it really does work.]
You now know which four-of-a-kind was removed.
Also – do try and track down the MOE AND HIS MIRACLES book – it is fascinating reading.
And check out the tribute site to this legend –