Blackjack Dealer's Hole-Card Switch
This blackjack switch is usually done when the dealer has a 10-up, and an unfavorable card in the hole. When a dealer's up card is a 10, he must first check his hole-card in case it is an ace. While checking his hole-card he is able to glimpse at the top card of the deck - if that one does happen to be an ace he can perform a hole-card switch and end up with a natural.
In this video a slightly different approach takes place, although the mechanics of the actual switch are the same as for the scenario described above. For practical purposes, the actions on the video have been reduced to a minimum. Following is a description of how this switch would be executed in a gaming situation.
Let's imagine there are a few active players seated at the table. The dealer is using a marked deck in which all the 10-value cards have been marked. The dealer will always know if the top card of the deck is a 10-card. He will attempt to catch a total of 20 during the deal be second dealing to the players any time there is a 10-card on top,. and therefore securing the 10-card to fall into his hand.
The distribution of the cards is not shown on this video, however, let's imagine that the dealer didn't happen to catch a 10-card while dealing the firs cards to the players. In this case there was no need to second dealing, unless the dealer wanted to take a second chance at catching a 10-card by second dealing his up-card. Whatever the scenario, our dealer happened to catch a 7 up-card.
After dealing his up-card he must proceed by dealing a second card to each one of the players. Since a 10-card has not yet been dealt out, the remainder of the deck is not richer in 10-value cards and there is an increased chance that the dealer will be able to catch a 10-card while dealing the second players' cards. As soon as the dealer spots (or feels, if the deck is pegged) a 10-card on top, he switches to second dealing and secures this card on top of the deck to fall into the dealer's hole-card position.
At this point the dealer knows he has a 10 in the hole (10S), he sees his up card (7C), and knows his total is 17. This is not the greatest total a dealer could wish for, especially because a dealer can not hit a 17 (even if he knows the top card would help), but luckily God invented peeking, stud-style second dealing, card dumping, and a hole-card switch.
Since the players see a 7-up they will take more hits than if the up card was a low one (provided they know something about blackjack). The dealer will have the opportunity to peek at the top card every time before a player asks for a hit card. If he sees a 4 or a 3 on top of the deck, he will second deal the hit cards from there on, and keep the desired card on top for himself.
That by itself is already a great edge, but our dealer has yet another trick up his sleeve (figuratively speaking). Every time one of the players busts (and there is always the chance that all players bust), the dealer will scoop up the dead hand after collecting the lost bet (first the money, then the cards). Every time the dealer scoops-up the busted player's cards he may dump of the top card of the deck into the dead hand, yet getting rid of some unwanted cards that way.
In our case we imagine that the dealer was able to secure the 4 of Diamonds. He switches his hole card and makes it seem as if there was a 4 in the hole, now totaling 11 (4D, 7C). The 10 of Spades that was originally in the hole is now on top of the deck. Since the dealer has a total of 11 (no longer a 17) he must take a hit. The 10 that was originally in the hole is not a hit card, and the dealer brings his total up to 21.