Asymmetry of card shirts

Take the deck and divide it into two parts, then give it to two spectators who have to pick one card from a foreign deck and put it into their deck. Then each viewer carefully shuffles his half of the deck of cards and gives it to you. You take a small scale and weigh one card from the first part of the deck and notice that one of the cards is heavier than the other. It turns out that a card that is heavier is the card that the viewer chose or vice versa. The same thing you do with the other part of the deck and determine the map that was chosen by another viewer.
The secret of the focus is that in this trick the asymmetry of the card's shirt pattern is used. Before showing the focus, unnoticeably fold the cards so that the drawing of the cards is oriented in one direction. In front of the audience, divide the deck into two parts, which you give to one and the other viewer so that the drawing of the cards in different parts of the deck is in different directions. Every spectator, pulling out a map from another viewer, does not suspect that he puts this card in the opposite direction of the shirt's design. As a result, as if the spectator did not shuffle the deck, the chosen card will always stand out with the asymmetry of the pattern of the card shirt. Scales are necessary to distract the attention of viewers.