A key aspect of table procedures is to ensure that cards are not viewed during shuffling or dealing. This is done because of the obvious advantage a cheating dealer would have from knowing what the top card is before any players see it. There are a number of ways that this can happen either by direct peeking or by the crooked dealer getting a glimpse during common table procedures.
The most common way is during the gathering of cards for shuffling. The crooked dealer will gather the cards together and while doing this glance at the first card or perhaps a few other important ones that are near the top of the deck. He will then arrange them to stay there during the shuffle and deal process giving him a huge advantage.
Another way is by looking at the bottom card. This can be done by simply holding the card firmly with your left thumb against the tips of your other fingers (the bubble ploy). The dealer can then “buckle” the outer right corner exposing its index if it is a face or ace. This is a very deceptive move that works extremely well.
The best way to help prevent this is by ensuring that all dealers burn their cards when they are dealt and when they expose for betting. This can greatly reduce opportunities for dealer peeking and it also makes the would-be cheat think twice about trying to cheat in your game. Another trick that helps is to use a deck that has been printed and tuned to work with peeking devices. Casinos often have their own specialized decks that are designed to work with their mirror systems. They will have a different offset for Q and J cards and a slightly different vertical position for Tens. This gives a clue to the device where they should be placed for optimal reading.