Randomness of Shufflemaster

Are Shufflemaster machines totally random or are they pseudo controlled by the casino similar to slot machines limiting the number of paying hands to whatever the casino wants? I've noticed several things that make me ask this question... the fact that the machine keeps track of every card (it can tell the dealer what card is missing), and that often, the card that would complete a big hand is in the adjacent hand. Also, the machine 'knows' how many players are at the table, as the dealer presses his 'complete' button after all the hands have been dealt. This post deals with Three Card Poker and Let it Ride.

Thanks. If this is a duplicate post, I apologize... please point me to the original.

Quote: phd

Are Shufflemaster machines totally random or are they pseudo controlled by the casino similar to slot machines limiting the number of paying hands to whatever the casino wants? I've noticed several things that make me ask this question... the fact that the machine keeps track of every card (it can tell the dealer what card is missing), and that often, the card that would complete a big hand is in the adjacent hand. Also, the machine 'knows' how many players are at the table, as the dealer presses his 'complete' button after all the hands have been dealt. This post deals with Three Card Poker and Let it Ride.

Thanks. If this is a duplicate post, I apologize... please point me to the original.

Hi! Start reading here and to the end (6-8 posts) for a very detailed discussion of what SHFL machines do in various modes.

Quote: phd

Are Shufflemaster machines totally random or are they pseudo controlled by the casino similar to slot machines limiting the number of paying hands to whatever the casino wants?

One more post on the subject:

Shufflemaster

Of course they are rigged. That's why the casinos pay such exorbitant lease fees.

Dealing with a single deck and 3 card hands, I think there should be about a 1 in 8 chance that a particular card that isn't in your hand will be in the hand to your left or right. Higher if we're talking about 2 outs instead of 1 (like a high or low complement of a straight flush, or the third of a kind). (Someone with stronger math could grind it out.)

I have yet to see any "totally random" shuffle, ever.

"totally random" shuffles are a very vaugue concept. It depends on what the machine is meant to do.. Match house shuffle, random number of cuts and mixes, perfect shuffle large piles, etc. Machines also have to be careful, as too many perfect shuffles could leave clumps of cards in the same order as they were when they were put in, leaving one who is good at tracking cards to get the advantage.

tricky concept IMO

Quote: ajemeister

Machines also have to be careful, as too many perfect shuffles could leave clumps of cards in the same order as they were

That's riffles, not shuffles.

As far as I know, elevator type machines (like an MD2 or MD3) do a Fisher-Yates shuffle. They're as random as the random number source that drives them. Any card in the starting deck can end up in any position in the shuffled deck.

My understanding is the wheel type machines (like a one2six or iDeal) do a variation on a Pile shuffle. My understanding is the method used is almost as good as a Fisher-Yates shuffle. It should also be much faster.

Machines like the Shuffle Tech ST1000 do a series of operations to mimic riffles and strips. This should be about as good as a typical (non-professional) hand shuffle. (A typical professional dealer hand shuffling will often incorporate an offset break or two, which should keep cards from getting "stuck" at the bottom or top of the deck.)

Inexpensive machines like this do a single riffle per pass, and in my experience, do it quite badly. In order to be effective, several passes would be required, as well as one or more strips and offset breaks. (These are also slow, noisy, and prone to jamming and flipping cards.)

I haven't gotten a good look at a DeckMate (or DeckMate2) to figure out what it does. I'm guessing it's an elevator shuffler.


While I haven't ever seen a totally random shuffle, some of the shuffles I've seen on poker tables are very very good. On most house banked games, I generally see weaker shuffles employed as a concession to time.