Peeking at Hole Cards

What is the gain from peeking
at hole cards?

Obviously the most valuable card to get a peek at is the dealer hole card. With this knowledge you can forget normal strategies. Hole-carding strategies tell you exactly how to play knowing both dealer cards. Theoretically the gain can be enormous with a SCORE of over 10,000. However, the practical gain is limited because:

• We will not see every downcard
• We cannot always play ideally. For example, if the dealer has 20 and you have 19 you cannot win without hitting. But hitting will draw enormous attention.
• Always betting insurance correctly will also draw attention.
• Sometimes we will obtain only partial information. For example, the card has or has not pips near the edge or corner.

This chart shows the advantages for single-deck and six-deck games assuming that we see 0, 1%, 5% and 10% of the dealer's hole cards. No card counting is used and play is ideal. We can see that in single-deck, if we see only 1 out of 100 cards we nearly break even. The advantage quickly increases with additional cards.

Sim details

• Six decks, 4.81/6 penetration, S17, DAS, 1 player, Basic Strategy and ideal HC strategy for six decks
• Single-deck, 3 players, 3 rounds, H17, Basic Strategy and ideal HC strategy for single-deck
• Two billion rounds each