CGFSELECTIVE SHUFFLING, an analysis
For years it has been known that if the dealer shuffles up when there is an excess of small cards remaining* in the deck that it hurts the player. This is known as selective shuffling. However, to my knowledge noone has ever done a major analysis of HOW MUCH such practices hurt the player.
Because of all the flapdoodle, rants and raves that have gone on in rec. gambling. blackjack over the last 4 months, I thought that it may be interesting to put an additional analysis mode (Mode 15) into the 1996 UBE. Hopefully, this will shed some LIGHT on the practice, as opposed to all the HEAT that we have seen lately.
For those of you that are not card counters, read the following chapter on the Cut Card Effect. It expresses some similar ideas in a simpler manner.
The idea behind selective shuffling revolves around the fact that when more of the aces and 10s are out of the deck, the odds shift to the house's favor.
If the dealer were to remove any of these cards from the deck before play, this would be stacking the deck and it would be obvious and legally recognized cheating. However,the dealer can accomplish EXACTLY the same thing by noting whether many aces or 10s were seen in the first few rounds. If so, the dealer deals out the rest of the small cards to the player's disadvantage. But if no aces or 10s were seen,then the dealer shuffles up short and denies the player access to these "good" cards.
The idea of CHEATING is a legal idea that is defined by the state legislature, the courts, and the gaming commission in the state of Nevada. According to Nevada law, this practice is NOT considered cheating on the part of the house. However,it is my personal opinion that it is the MORAL EQUIVALENT of cheating. This is also the opinion of the vast majorityof blackjack experts, whether they are players or work for the gaming industry (see the June,95 issue of Blackjack Forum).
In Nevada, their are MANY casinos that do not engage in this practice under any circumstances (The Aladdin comes quickly to mind). However, there are unfortunately some that do.
If one is a skilled card counter, this practice is immediately obvious, and he or she can leave the table. What concerns me more is what happens to the poor BASIC player who does not know what is being done.
While this has been known for years, exactly HOW MUCH it hurts has not been. Therefore, I decided to do some simulations to see exactly what the damage was.
Also, note that selective shuffling can be done in the PLAYER'S favor. It is simply done by shuffling up when all the aces and 10s are out of the deck, leaving only low cards for the player.
For the non-counter, the deck is good card rich when the count is positive, and good card poor when the count is negative.
In the simulations below, I used Bryce Carlson's Omega II count in a single deck, head's up game with a normal penetration to 20 cards before the shuffle .Rules were downtown vegas, or double any 2, HS17.
In the HOUSE FAVORED selective shuffle, the dealer would shuffle at 1/2 deck (26 cards) if the true count was greater than 1, and it would not shuffle until 13 cards remained if the count was below -1. For a count between +/- 1, the prescribed shuffle point of 20 cards were used.
In the PLAYER FAVORED shuffle, the opposite was done. When the count was high, the dealer waited to 13 cards for a shuffle. When it was low, the dealer shuffled at 1/2 deck.
The results are stated below:
TOTAL ROUNDS 100,000,000
Penetration to 20 cards from end, no selective shuffle
bet INITIAL BET AMOUNT BET AMOUNT W/L I%W/L T%W/L
STD
1:1 $100,000,000 $112,808,607 $266,880.50 .27% .24%
.01%
2:1 $136,222,291 $154,509,071 $1,216,910.00 .89% .79%
.02%
4:1 $197,361,942 $225,153,258 $3,049,132.00 1.54% 1.35%
.02%
House favored
Selective shuffle, deal at 26 cards if +, 13 cards if - .
1:1 $100,000,000 $112,174,400 -$387,415.50 -.39% -.35%
.01%
2:1 $128,595,230 $144,962,783 $189,510.00 .15% .13%
.02%
4:1 $175,491,223 $198,928,241 $1,291,022.50 .74% .65%
.02%
Player favored
Selective shuffle, deal at 13 cards if +, 26 cards if -
1:1 $100,000,000 $113,292,699 $862,346.50 .86% .76%
.01%
2:1 $142,957,699 $162,897,531 $2,254,660.50 1.58% 1.38%
.02%
4:1 $217,824,150 $249,637,437 $4,972,376.50 2.28% 1.99%
.02%
The results were recalculated for a 1:1, 2:1, and a 4:1 spread.
The i%w/l is the percentage as a function of the INITIAL bet, and t%w/l is the percentage as a function of the TOTAL amount bet.
Note that a dealer could use this to build up a bank witha house favored shuffle, and then throw the money to aconfederate with a player favored shuffle.
Also, note that with the house favored shuffle, the player is still UP AT THE END OF THE DAY with anything except a flat bet. The player may not be up by MUCH, but he is UP. For the skilled player, it sticks out like a sore thumb. But what happens to the poor BASIC player?
The 3 runs below were done using the same criteria as above, except that the PLAYER is playing BASIC strategy and the DEALER is counting cards using the Omega II. Shuffle up criteria for dealer and player favored shuffles are the same as in the examples above.
TOTAL ROUNDS 100,000,000
INITIAL BET AMOUNT BET AMOUNT W/L I%W/L T%W/L
STD
NOps $100,000,000 $112,049,392 -$326,712.50 -.33% -.29%
.01%
Hfs $100,000,000 $112,559,321 -$830,322.00 -.83% -.74%
.01%
Pfs $100,000,000 $111,444,695 $252,048.00 .25% .23%
.01%
NOps means NO preferential shuffle. Hfs means house favored shuffle. Pfs means player favored shuffle.
Note that for the player, the game has now been turned into a LOUSY shoe game.
Also, note that the expectation for the normal, nonselective shuffle is considerably less than the normally published expectation of -.19% . This is due to the cut card effect.
I will probably have more to say on this in the future .However, for now I respectfully suggest that the gaming commission, the Nevada state courts, and the legislature reconsider their position on this practice. While it is not legally defined as cheating, it certainly gives the appearance of cheating. I respect the fact that the house needs to protect it's games. However, this SLEAZY but legal practice should not be one way of doing so, any more than removing an ace or 2 from the deck when the house decides that there is a card counter at the table.
John H. Imming, Jr.
*Vampire's note:- John presumably meant an excess of aces and tens