This is a tremendously visual effect developed by Dai Vernon using the Elmsley Count. The aces one by one turn face-up while the four aces are merely shown and counted. For the climax the black aces change place with the red aces while they are resting in the spectators hand.
If you want an even more visual twisting effect, then take a look at Waving the Aces by Guy Hollingworth.
runtime: 4min 14s