Shuffle Machines - 102

(Continuing Education about Card-shuffling Devices used in Blackjack)

by Ron Fitch --- a.k.a. Boris

Sometime ago I wrote a web-article for the Shuffle Machine section of Boris' website entitled "Shuffle Machines 101"; although it got lost in the shuffle (pun intended) of the articles that eventually made up the Shuffle Machine section. At the time I wrote the 101-article, I had not seen the patent diagrams behind this article, making it at best a cursory introduction to the subject.

Ironically, a couple of years ago, I used to receive e-mails from people around the world claiming to work for ShuffleMaster or disgruntled employees of JNU (I believe in Austrailia), eventually bought by ShuffleMaster.

The jist of their e-mails would be something on the order of:

 "the material in the shuffle machine section is a buncha CRAP";

to which I would reply something on the order of:

"I pride myself on the accuracy of my website and the Boris for Blackjack software. Would you please detail which facts I have wrong and I will be happy to correct them".

The response to my replies? SILENCE.

Does that tell us something? Or WHAT?


This year (2006), in time for my annual "April Fool's" Joke on BorisBJ21.Com, I again found myself at the USPTO website doing extensive research into the myriad of shuffle-machine related patents (there are 70 references alone listed in patent # 6,651,982 B2). The USPTO website uses TIFF file format exclusively, requiring a 3rd-party add-on (luckily available in freeware).

Just because a device is patented, is no guarantee that it will ever make its way into a fully-viable commercial product. Many of the 70 patents date back to the late 1920's and 1930's describing hand-cranked monstrosities, with a bunch dating in the 1950's & 60's. I found it interesting research to study each of these patents, even though the majority of them have no application in today's live casino play.

Boiling it all down, it seems that since 1988, we have seen a dozen viable shuffle machines used in live casino play. Suprisingly, ShuffleMaster I & II were not the first machines to the market place. In more-or-less chronological order we have the following units (all dates approximate):

  1. 1990: The Stack shuffler, patented in 1988 - what I colloquially refer to as the "whale box" or white-box unit.

  2. 1992: ShuffleMaster I (for single-deck games).

  3. 1993: ShuffleMaster II (for double-deck games).

  4. 1996: ShuffleMaster MD-1, what they call a batch shuffler - what I colloquially refer to as the "ShuffleMaster BOX".

  5. 1997: Casinovation's Random Ejection Shuffler.

  6. 1998: Proshuffle's PRO Shuffler.

  7. 1999: The Quickdraw Shuffler (rights now owned by ShuffleMaster)

  8. 2000: ShuffleMaster's Ace/King shelf shufflers.

  9. 2000: The ShuffleStar Shuffle unit, popular in Europe (rights now owned or shared by ShuffleMaster).

  10. 2003: ShuffleMaster's DeckMate Shuffler mainly used for 1 and 2 Decks (although it can handle more).

  11. 2004: ShuffleMaster's One-2-Six carousel shuffler.


Key technology found in these units include:


The main impetus behind my shuffle machine interest is the Boris for Blackjack Simulation Software. Since 1992, Boris has included one or more shuffle machine casino entries; beginning with SM-1 and SM-2, followed by SM-BOX. Later, I added in the batch-version of the Random Ejection Shuffler.

As I write this article, I am in the process of implementing ShuffleMaster's KING & One-2-SIXtm shufflers in Boris; to be followed shortly by the continuous variation of the Random Ejection Shuffler; which software-wise is a different animal altogether, even though it still uses the ejection process.

Because the ShuffleStar and DeckMate shufflers are not yet popular offerings in U.S. and Canadian casinos, they have been relegated to secondary design status to appear in a future software update.

Similar to the Shuffle Machines 101 article, to give you a thorough overview of all these shuffle machines, I will detail them in groups, as many of the units have base-functionality in common.

Let's begin with the early/original ShuffleMaster units.

Mechanical Fingers
The original ShuffleMaster I & II units (SM-I/SM-II) utilized a mechanical finger method to simulate the riffle/cut process performed by a dealer when hand-shuffling 1 or 2 decks. Additionally, an attachment allowed the unit to "spit out" cards in 3 or 5 card groups; useful for producing 3-card hands for Let-It-Ride and 5-card hands for games like Caribbean Stud. While one pack of cards is being played, a second pack is in the machine being shuffled, virtually reducing "downtime"; one of the major benefits of all shuffle machines.

Armed with this knowledge, a few astute players discovered ways to arrange cards on discard hands to take advantage of the riffle procedure produced by the SM-1 units. In Bally's Vegas 1992 trial of SM-I in Blackjack (at $2/$5 tables - chump change for a casino like Bally's) I discovered ways to "encourage" the cards to "jam" the machine when a deck began to produce a consistent dealer bias. I detail this more thoroughly in my original article The Invasion of ShuffleMaster.

Casinos offering double-deck games such as the Barbary Coast in Las Vegas quickly adopted ShuffleMaster II to benefit from ShuffleMaster's promise of up to 38% more hands-per-hour. Because the house has an advantage over most players, increasing the hands-per-hour is tantamount to increasing the table "hold".

Ironically, many casinos including the Barbary Coast discovered that additional hands-per-hour, may not necessarily produce the kind of hold available from using a tailored shuffle; such as their unbalanced riffle. Within a year they had removed the SM-II units (although they kept the SM-Box shuffler for their 6-Deck games).

New York New York in Las Vegas removed their SM-II units in favor of using the BOX shuffler for their double-deck games; ostensibly to reduce monthly-rental costs. A series of comparative blind-simulations using Boris for Blackjack demonstrated that the $500/mo. rental had NOTHING to do with SM-II's removal. As it turns out, 2-Deck "Box" games tend to produce higher profits than their SM-II counterparts; and that, my friends, is the bottom-line - increased profit$ being the bottom-line.

Elevators to the rescue
With the introduction of the MD-1 batch shuffler (what I call the "ShuffleMaster BOX"), ShuffleMaster brought forth a method for shuffling 4, 6 or even 8 decks of cards using a unique 3-elevator method, simulating the riffle produced by SM-I and SM-II. The machine was so successful that at one time Caesars Atlantic City was offering nothing but 8-deck BOX games; and, I believe it was the Sands who risked dealing a 4-Deck BOX game in their high-stakes room (high-stakes for the Sands, at any rate).

As detailed in the web-article Inside ShuffleMaster BOX", the randomly produced machine parameters can create anything from a super-random Blackjack game all the way to one which is highly clumped (i.e., non-random).

Like SM-I and SM-II, the BOX shuffler utilizes two sets of cards; meaning that in the shoe game we end up with TWO "game signatures"; relevant to most styles of clump-track play. When I come into a new table with a BOX shuffler, I will often ask the players at the table whether the Red (or Blue) cards from the previous shoe (before I entered the table) were "hot" or "cold". This information can be useful in determining whether a pack of cards has developed a bias, one way or the other.

Overall, I find the BOX games to be worth scouting for serious play; unless the casino is resorting to a double-pass shuffle (cards shuffled twice, often resulting in the re-introduction of downtime), as seen at the El Dorado Hotel in Reno some years ago.

Other Riffle Simulations
Thus far we have looked at shuffle machine approaches which essentially simulate a two-pick riffle process. There is one more unit which fits this bill although while it has existed since 1998, it has gained little popularity, compared to the ShuffleMaster units; this is the PRO Shuffler. This machine is essentially a bottom-feed riffle shuffler.

According to the manufacturer, the PRO Shuffler has two advantages:

Because the PRO shuffler is so quick, in reality only a single pack of cards is needed (instead of two for the BOX shuffler). Unfortunately, the PRO Shuffler simulates a simple, straight-thru shuffle; the easiest for shuffle trackers to take advantage of.

Casino solutions to this problem is to either run the cards thru the machine multiple times, or split the stacks into zones, restacking them before loading into the shuffle machine - the method I saw utilized at [off-strip] Sam's Town casino in Las Vegas. In extreme cases, a quick 1-riffle zone shuffle before the machine gets the cards solves the problem; unfortunately, at the expense of downtime, negating much of the PRO shuffler's benefit.

Missles and Ejectors
The 1990's ended with the introduction of Casinovation's Random Ejection Shuffler, although technically, it is based on ideas from several patents. This machine is the brainchild of Steve Forte, a casino consultant who began his involvement in casino gaming on the player's side of the tables (you might recall that he is the author of Read the Dealer, the book that eventually forced casinos to adopt the now ubiquitous, holecard "peek" devices, found on most Blackjack tables today.

Unlike the units described thus far in this article the Random Ejection unit (as well as the units described in the rest of this article) really do seem to produce Random cards. With the early ShuffleMaster Units I dispute ShuffleMaster's claim to random cards. Their definition of random and our definition of random are describing two different phenomenon entirely.

Jerry Patterson's Blackjack: a Winner's Handbook (2002 Edition) is an excellent re-release of his 1990 Edition, sporting a chapter on Shuffle Machines, which graciously gives me and Boris a nice plug, for which I am grateful. Unfortunately, this chapter is riddled with errors, and is arguably the most questionable chapter, in what is otherwise a largely well-written book. I will have more to say about this when we look at the KING Shuffler.

On P.166 Jerry overall misquotes me, when he writes

"Ron has acquired patent diagrams for all ShuffleMaster machines and for the PRO shuffler and the Random Ejection Shuffler.

Using his software to simulate the shuffles, he claims to have demonstrated that ShuffleMaster I, II and BOX can be beaten under certain conditions".

So far so good...... But then he continues...

"On the other hand, his simulation of the Random Ejection Shuffler seems to validate that the machine produces random cards, but then, after further review, he finds that, like ShuffleMaster BOX, many games appear random only to clump up later, depending upon the intertwine factors selected for the last several shuffles"

- interesting.... except it's NOT true, and, having personally programmed the REJ shuffler into Boris for Blackjack (based on patent diagram study and live observation of several machines in action), I would never have made such a claim.

Ironically, to Jerry's credit, I believe the Random Ejection Shuffler CAN be beaten (or at least reduced to break-even status), from using carefully-chosen 3-bet progressions, or a modified approach to Boris' B.U.R.P. (Boris' Universal Reverse Progression) method coupled with Blackjack 2000 (a Basic Strategy variant) from Jerry's book.

With the Random Ejection Shuffler because the cards are ejected randomly with "missles" (as they are colloquially called), or "ejectors", if you prefer, there is no such thing as an Intertwine-factor, as we observe with the ShuffleMaster BOX.

The Random Ejection Shuffler takes a unique approach to card-shuffling which begins by loading the cards face down into the back of the machine onto a moveable tray sloped into the unit itself.

Per the patent diagrams, the cards are positioned over 1 of 6 hammers (or if you will, ejectors) designed to push a single-card OUT of the pack, up into its corresponding curved column (or channel); the bunch of which look like a translucent snail-shell. Ejected cards travel upside down through these columns, to be stacked right-side up in a single stack (or tier) of cards, which are then removed from the machine.

Each channel/column sports a different arc-radius; the rear columns bearing a larger-radius, requiring lengthier travel time for the card after being ejected, until it finally lands on the stack. This time differential is part of the "randomness" of the machine.

Between the movement of the input tray, the random hammer selection and different travel speed, for all intents and purposes, the Random Ejection Shuffler, when used in "batch" mode does seem to produce random cards. This is borne out in the Boris for Blackjack simulation software

(Note: Boris users can go to the Casino Management screen and change the Shuffle-Code to "J4" to play against the REJ shuffler.).

As you can see, there is no such thing as an intertwine-factor with this shuffle machine.

An attachment to the Random Ejection Shuffler allows it to operate as a continuous shuffler. You may have seen one of these continuously-shuffled games and not known it. For example, at Harrahs in Laughlin Nevada they deal what looks like a 2-deck game, which is in fact dealt from 8-decks, shuffled by the Ejection Shuffler and dealt 2-decks at a time with about 75% penetration per-pack. Depending on the kind of wash used and other factors, I believe this double-deck has win-potential.


Card Insertion Machines
There are essentially two shuffle machines, which use what I will call a/the card-insertion technique. Essentially, this involves "opening up" a stack of cards at randomly selected points and inserting one or more to-be-shuffled cards.

The ShuffleStar unit (originally manufactured by CARD in Austria) positions the cards horizontally in a channel, which is front-ended by a shoe attachment. Cards to be shuffled are positioned randomly to the left of the cards to-be-played and randomly inserted horizontally.

Because of the design of the unit (according to the patent diagrams), there may be an opportunity to slightly exploit what is known in statistics as "latency of re-distribution" of approximately 1 to 1.5 decks in length.

The other shuffle machine variation using the insertion-method is known by the name of QuickDraw; technically now also owned by ShuffleMaster. QuickDraw is really no different from the CARD Shuffler, except that the cards are inserted & stacked Vertically before being peeled-off one-at-a-time into its built-in shoe front-end.

With QuickDraw, discards are stuffed into the top-front of the machine. Cards already inside the machine are "lifted" at random points where individual cards are inserted, creating a more-or-less random distribution.

Based on patent diagram drawings, like ShuffleStar, I believe there is a potential latency of re-distribution with the QuickDraw shuffler as well; my estimate being approx. 2-decks worth.

It will take a carefully run simulation with Boris for Blackjack to tell us whether there is an exploitable latency with these units. For more information on the subject of latency of re-distribution, consult Chapter 9 (Buck Rogers Blackjack - machine vs. counter) of John May's book Get the Edge at Blackjack (Pp. 79-87).

While I contest the application of May's material against the KING shuffler, ironically, like with Patterson, his material may still have application elsewhere; in this case, with the early insertion shufflers.

Now technically, with the somewhat recent appearance of the ShuffleMaster's DECKMATE shuffler we have a 3rd approach to insertion shuffling. I would truly call this last method the lift-and-separate approach, although it sounds like a commercial for a brassiere.

In my opinion, the DeckMate shuffler possesses all the "randomization" features of the QuickDraw unit (which ShuffleMaster now owns) without the latency of redistribution problem, in that DeckMate is a "batch" shuffler (meaning the batch of cards is then hand-delivered by the dealer to an external dealing shoe).

I guess if you think about it, with DeckMate, ShuffleMaster "gets the best of all possible worlds", to paraphrase an old philosopher; who's name escapes me at the moment.

Shelf stacking and Carousel Shuffle Machines
I round out our look at shuffle machine categories by stepping back a few years as we visit two unique ideas: shelf-stacking and carousel-insertion.

Shelf stacking is accomplished by stripping off single cards from an input stack and inserting then on one of a number of "shelves". Then, as needed, each shelf is randomly unloaded into the dealing-shoe mechanism. Currently, only ShuffleMaster uses this method.

Technically, the shelf stack approach was first utilized by the white-box, which additionally, was the first continuous shuffler on the market; amazing since the original ShuffleMaster units were still an "evil gleam" in the eyes of John Breeding, the assignee of the original SM-I and SM-II patents and founder of ShuffleMaster Corp.

In John May's book he points out that the white box shufflers were indeed exploitable. I first encountered these units at the Golden Nugget in downtown Vegas in 1991. By the mid-90's they had been moved to the Mirage on the strip, relegated to a side Blackjack pit. I recall reading about a Blackjack team who made their profit$ from those machines at the Mirage before they quietly disappeared.

Having seen these machines in operation with their cover off, and having studied the patent drawings for the unit, I am at a loss as to how a latency of redistribution can occur; however, I will take John's word for it. Virtually overnight, these machines disappeared, to my knowledge, never to see a casino floor ever again.

Currently, the ACE shuffler (for 1-deck games) and KING shuffler (using 4 or 5 decks) have perfected the idea of "card sorting". Amongst the 70 patents I mentioned earlier are a number of ideas for "sorting cards".

While those patents usually referred to sorting computer cards or document collation, if you study them closely and then restudy the Ace/King diagrams, you can actually see that shuffle machine shelf stacking is a high-tech recreation of a number of old ideas.

As an aside, I wouldn't be surprised to see ShuffleMaster enforce this patent on a myriad of non-casino venues; one of the [sic] main reasons patents are written as vague and generalized as they can get away with.

What I find interesting about the KING Shuffler is that it contains 19 shelves; 19 being a prime number; [the use of] prime numbers being desirable in random number generation; which is crucial to ShuffleMaster's claim to randomness.

Being a professional software developer, I get a kick out of ShuffleMaster's marketing "smoke" about their use of [sic] 64-bit random number generation, when in fact, they are generating only two entries per card-insertion: a value from 1 to 19 for determining which shelf a card should be placed on, followed by another value to determine whether the card is placed on-top .vs. underneath any cards already on the shelf.

While ShuffleMaster has all but saturated the market with its various shuffle machines (they own, or own rights to nearly every machine commercially available), it is arguable that the Ace & King units are currently their best movers.

With the Ace shuffler, dealing hands for games like Let-it-Ride, 3&4 card poker and Caribbean Stud is a SNAP. Not only does it speed up the game, it virtually eliminates hand dealing errors, as the dealer simply gives a pre-made hand of cards from the shuffler directly to the player.

Of course because ShuffleMaster owns the rights to all the above-mentioned games (except Caribbean Stud), to obtain "license" to offer their game in the first place, game operation must include an Ace (or other ShuffleMaster) shuffle unit.

When you own the ballpark as well as the baseball team, you can pretty much dictate what you wish. Lest we ignore it, the Ace shuffler is also useful in an obscure little game known as Blackjack.

Now, depending upon your point of view, the introduction of the ShuffleMaster KING has had a devastating-effect on the game of Blackjack. Because of the way in which the cards are inserted on the shelves from an input hopper, KING essentially introduces the concept of continuous-shuffling as we saw with the 8-Deck double-deck Random Ejection shuffled game, but without any risk of latency of redistribution.

In my talks with players and casino management alike it is clear that early KING shufflers had some serious mechanical problems. In the 2000 - 2001 era, it was not uncommon to see a unit with its covers off; which brings me to an important point.

In Jerry Patterson's aforementioned "Winner's Handbook", his chapter on shuffle machines gives a completely erroneous description of how the KING shuffler operates.

Ironically, again, I know the "007" character Jerry refers to. Being a Boris software user, Mr. Bond and I have traded numerous e-mail exchanges over the years, leaving me with nothing but respect for his Blackjack acumen. Unfortunately, regarding the KING shuffler, he has it all wrong - it makes me wonder what he was smoking while on the deck of that cruise ship.

Bond talks about the cards being "clamped off" and eventually moving down in sequence toward the bottom. Who knows, maybe that was an early (now discontinued) prototype of the machine, but that is not how the KING operates, if you study the patent diagrams and descriptions of the unit.

Aside from those mistakes, Patterson's comments on exploiting a machine near the end of its "cleaning cycle" may have some merit. It will take some careful record-keeping (as part of your table scouting) in order to discover this, because unfortunately, simulating a [sic] "dirty" shuffle machine is beyond my ability as a software developer. It is one thing to program in the effects of humidity on a hand shuffle; it is yet another domain entirely to program in the effects of wear and misalignment in a shuffle mechanism.

Continuous shuffling is LOADED with pros and cons.
With the KING shuffler, the dealer can put discards into the input hopper at any stage of the game, creating in-effect a continuous-shoe. Because there is no shuffle-card, card-counting success is virtually eliminated. Card-counters require "penetration" in order to jump their bets. I guess we could say that card counters are in effect looking for a sort of latency of redistribution; not possible with properly executed shelf stacking.

With the KING shuffler, as long as the dealer inserts the discards back into the machine every round there is no possibility of an exploitable latency. In a 7-player game, if two-rounds or more are left in the discard tray before being reshuffled, the latency of redistribution problem resurfaces.

 Jerry Patterson quoted me as saying that I thought the machine may be producing clumped cards. While I do remember suggesting that early on in my observations, having since observed a multitude of KING games, unless there is something I am missing, cards produced by this unit are essentially random. We shall have a definitive answer to this question after I introduce the KING shuffler into the Boris for Blackjack software this summer.

As for the cons to this shuffler, I have already mentioned the mechanical problems, although they may well be a thing of the past. As it turns out, most dealers hate the continuous shufflers. Hand shuffling gives the dealer a break from the tedium of the game, lost with a continuous shuffler; but what do casino managers care - dealers are just minimum-wage (plus tips - paid by the players) employees.
(As a side note, Patterson tells us in his 1990 Winner's Handbook that on the island of Macao, because the cards are shuffled by two dealers, they often stop first and have a spot of tea before shuffling - I kid you not; probably the reason Macao Blackjack is literally the slowest (hands-per-hour) game in the world.)

While the KING shufflers have gained in popularity (casinos like the PALA Indian casino in California use SMBOX for their green/black chip games and a bevy of KING shufflers at their lower stakes Blackjack tables) other casinos (such as the Venetian in Las Vegas) have removed the KING units altogether, while leaving the BOX shufflers in play; probably because high-roller players don't trust continuous shufflers.

102 Conclusions
In a near dozen pages we have looked at virtually all, existing commercial shuffle machine units, past and present. We have seen that there are a number of different ways to mechanically shuffle cards, each with pluses and minuses.

While it is my belief that shuffle machines will never completely replace hand shuffling, machine technology is with us to stay. You should either find a reliable method to exploit the above-detailed weaknesses, or, avoid these games altogether. In my Blackjack world, research is on-going.

Personally, I still find the 6 & 8 deck BOX games to be overall playable and am looking into the 2-Deck-8 variation of the Random Ejection shuffler. With the help of Boris for Blackjack, 2006 should give us some interesting answers. Stay Tuned.





Latency of Redistribution

According to Get the Edge at BLACKJACK (P. 80) John May describes "latency of redistribution" as it applies to continuous shuffle machines as follows:

In layman's terms, this means cards played on one round probably won't appear on the next. Exactly when the cards find their way back into the shuffle depends on the number of players, the speed of play, and most importantly the variety of machine itself.