CASINO-OLOGY: Blackjack Single-Deck Games of the 70s Had a Built-in Advantage

This edition of Casino-Ology from expert Bill Zender (l.) is a fascinating historical breakdown of how pre-1980s single-deck blackjack games had quantifiable advantages because of dealers’ practice of physically lifting hole-cards and the effects that had on hand cutting.

CASINO-OLOGY: Blackjack Single-Deck Games of the 70s Had a Built-in Advantage

I used to get tired of listening to “old timer” casino executives brag about how they did so well with single-deck pitch games prior to the 1980s. I used to hear, “We would dealer pitch single deck, keep the cards in the air, and make nothing but money.” Holding “20 percent-plus” was mentioned a lot, too.

This was usually a comment made by the table game veterans whenever the multi-deck blackjack games I was managing were struggling to hold 15 to 16 percent. It wasn’t until several years later that I realized that due to the procedures of looking at the hole-card and the process of hand cutting the deck provided the pre-1980s blackjack games with a built-in mathematical advantage.

Dealers used to manually look under tens and aces.

Today, almost every blackjack game, where the procedures dictate the dealer takes a hole-card, utilizes a hole-card peeking device to see the value of the hole-card when the dealer has a ten value or ace as the up-card. This device requires the dealer to slide the corner of his or her two-card hand into the peeking device. This is accomplished without lifting or bending the cards, and in addition, limits the information to whether the dealer has a round-ending two-card blackjack.

Note: The casino industry did go through a period in the late 1980s and early 1990s where the casino opted to NOT look under their hole-cards, but it was soon realized that failure to do so caused the casinos to continue rounds that had already been decided and that issue cost the casinos revenue due to lost rounds.

Prior to the 1990s, before hole-card peeking devices, the casino required that the dealer manually look under the hole-card to determine if the dealer held a two-card blackjack. This was accomplished by the dealer lifting the lower left corner of both the up-card and hole-card together with his or her right thumb and elevating the two cards high enough where the dealer was able to see the value on the index corner of the hole-card.

Because the casino did not want the value of the hole-card exposed to players at the table, the dealer would use his or her left hand to block the view from any exposure to the left side of the table. Since the dealer had to lift and slightly bend the cards to see the bottom card, both cards would then be physically warped by the action, resulting in what one would call at that time “dealer bends.”

Any tens or ace card would develop a unique bend or warp due to the dealers lifting the ten and ace cards when checking for a two-card blackjack. This bend appeared different when comparing the ten/ace and non-ten/ace cards. The ten/ace cards, when laid on the table face down, would appear to resemble a small bridge with the playing card ends touching the felt and the middle section slightly elevated off the table.

The non ten/ace cards would be bent in a different direction and would resemble more of a “dip chip” with the ends slightly raised above the table and the middle section of the playing card touching the felt. If these bends were noticeable enough, the knowledgeable player could use this information for making critical playing strategies as well as more accurate insurance decisions.

Players used to be required to hand-cut the deck of cards.

Prior to the 1980s, the standard single-deck (and double-deck) games were cut by the players by hand. The dealer would place the shuffled deck of cards on the layout in front of the intended cutting player. The player would then reach down and cut the deck to the right or left of where it was placed on the table. Once cut by the player, the dealer would pick up the bottom portion of the deck and transfer or finish the cut. The dealer would then place the cards into his or her hand, burn the top card, usually to the bottom of the deck, and start dealing the cards.

To facilitate the cutting action, the player would reach down and grab the length side of the cards with the fingertips. As the player lifted upward, a portion of the playing cards would separate from a portion of the cards that remained on the table. Where the cards would separate relied on a couple of issues such as finger pressure and point where the player intended to cut the cards. However, one issue would dominate the exact point where two cards would separate to break the cards apart, and that had to do with the way the cards had been physically distorted due to peeking the hole-card.

The most likely break point was directly under a playing card that was bridged. The gap in the middle of the bridged playing cards allowed for the cards to separate with the least amount of friction. If the deck of playing cards had been in use on a blackjack table for 30 minutes or more, a large portion of the tens and aces would be bridged and they would be favorable to the cut separation.

When experimenting with the hand cutting process, it was noted that after the deck had been in use for a half-hour or more, an overwhelming majority of hand cuts resulted in a ten/ace being transferred to the bottom of the deck. In essence, after a short period of time in play, the average player cutting the deck in a normal manner would automatically cut either a ten value or an ace to the bottom of the freshly shuffled deck and out of play.

What effect does removal of a ten or ace have on the mathematical advantage of blackjack?

Based on information obtained from Peter Griffin’s Theory of Blackjack (1978), the removal of one ten or one ace from a 52-card deck is a change in the blackjack game’s mathematical house advantage by about half of one percent (0.51 and 0.61 percent, respectively). During the hand cutting process after the playing cards have been in use for a short period of time, there was a very high likelihood that the player cutting the cards would inadvertently cut a ten or ace value card out of play and provide the house with an increased advantage of about 0.5 percent.

Griffin provided the public with a host of information with the release of this book. One of the projects outlined in Griffin’s book was to establish an accurate mathematical house advantage for the more popular blackjack game at the time, which was a single deck of cards utilizing common rules. Common rules included standing on all 17s, doubling down on any two cards, splitting aces one time and receiving one card on each, and two-card blackjacks that paid 3:2.

Griffin programmed a mainframe computer to play blackjack and then inserted a data array of 52 data points, representing the 52 playing cards of a standard poker deck. He next programmed the computer to play what was considered in the 1970s a perfect strategy, known as basic strategy.

After running 500,000 hand simulations on the computer (today mathematicians would run a minimum of 100 million hand simulations), Griffin found that the single-deck blackjack game under the above-mentioned rules and strategy was basically a dead even game. Griffin was also able to analyze the effect of removal of various individual playing cards from the deck which was mentioned two paragraphs earlier.

What Griffin’s information indicates is that the hand-cut single-deck game, which had a beginning mathematical advantage as “dead even” between house and player, was functionally elevated to a 0.5 percentage house advantage game due to the procedure of physically checking the dealer’s hole-card and the hand deck cutting process.

This strange little tidbit indicates that during most hands being played on the single-deck blackjack game prior to the 1990s, that single-deck game with basically neutral blackjack rules operated with the same mathematical advantage as many of the multiple-deck 3:2 blackjack games do today. Throw in the fact that the average blackjack player prior to the 80s had a limited understanding of blackjack basic strategy (or common strategy for that manner), it is easy to see why “early years” casino executives could hold 20 percent and win “all the money” with single-deck pitch blackjack games.

Side note: During my card-counting days I was aware of the effects of dealer bends when cutting the deck cut so I would always cut the deck towards the ends and away from the middle of the cards. Later in my advantage play period, I would attempt to use the cut problem to my advantage. Sitting in an early position on the table, I would purposely cut to a bend, and then with my right thumb, rifle down two cards before completing the cut. Why two cards? The two cards represented the card to be burnt off the top of the deck and the second card left the ten/ace card to be delivered as my first card. If I could steer a ten-value card or ace into my hand as my first card, I would start the hand with a known 20 percent advantage.

Articles by Author: Bill Zender

As former Nevada Gaming Control Agent, casino operator, professional card counter and casino consultant, Bill Zender has been involved in various areas of gaming and hospitality since 1976. In the past, Zender has instructed courses on game protection, card counting, advantage play and gaming operations at various colleges and institutions throughout the country. As a member of JMJ, Inc., Zender was an owner and operator of the Aladdin Hotel and Casino and has additional operational experience in card room casinos in California and is considered an expert in Asian gaming. Besides his practical gaming experience, Zender holds a bachelors in hotel administration and a masters in business. As a gaming author Zender has penned seven non-fiction books on gaming including Card Counting for the Casino Executive, and the Casino-ology series. Owner/consultant of Bill Zender and Associates, Zender spent was general manager at a major California cardroom casino from 2018-2019. For more information, visit