Card Patterns in Online Poker

[Collin O'Mahon]

I've been playing Holdem extensively at PartyPoker for several months. There have been numerous occasions wherein I have been dealt the same hole cards twice in a row.

It would seem that the probability of being dealt the same hole cards twice in a row would be less in a b&m room, as the cards are physically shuffled. Physically, although the shuffling is itself a random process (if done correctly), it would seem that a proper shuffle would tend to distribute the cards differently than any previous, or subsequent, shuffle. However, the random number generators used by the online sites don't take this into account. Is this an accurate protrayal of b&m reality?

[Copernicus]

If you are saying that a "random" physical shuffle would tend to separate hole cards, whereas a generated distribution would not know their prior position, I disagree (on the physical side). To be dealt the same cards twice in a row they are in fact separated between hands...they have become n apart whereas they were together in the muck.

A random physical shuffle will initially separate the cards, but they still have the possibility of returning to n apart (where n is the number of players) and dealt to the same hand, or they could return any other number apart and not appear in the same hand.

I havent noticed any pattern of hole cards repeating online. The only "aberration" that I noticed early on in my online days was an apparent tendency for board pairs to repeat, but I doubt that the occurrences were anything other than normal.

[Collin O'Mahon]

Thanks. Good explanation, very clear. I tend to agree now that "aberrations" seen online are simply a function of (a) more hands played online (many more hands seen), and (b) not much time spent in b&m cardrooms.

[PAUL-IN]

in an online cardroom, you will generally see many more hands per hour than in a b+m cardroom. because of the larger amount of hands, "strange" things occurr, such as same flops, one after the other, or same holecards. but the probablility of being dealt the same hole cards twice in a row should statistically be equal to that in a b+m cardroom, unless the shuffling algortithm PartyPoker uses is bugged.

[Collin O'Mahon]

Nothing is truly random. The question, really, is how closely one approximates, or simulates, randomness. The physical shuffle and the RNG algorithm used online are both simulations of randomness. However, it is possible that the accuracy of the simulations may differ. It may not be apparent, even using statistical measurements (i.e., the process is "mostly" random, in that certain patterns are not appearing more or less frequently on average then statistical predictions would suggest).

However, I'm wondering if the physical shuffling process in a b&m cardroom is a less "random" simulation than a software algorithm, generally speaking. For example, there are many variables in the physical suffling mechanism that will affect randomness (for lack of a better abstract term). Length of shuffle, number of cuts, dealer exertion, friction between the cards (themselves and the table), quality of table covering, etc. etc. etc. These variables are not included in the software algorithm, I would expect, and thus the relative "randomness" will differ.

Of course, if the distribution of hole cards (or complete hands) in a b&m cardroom is reasonably similar to what may be statistically predicted, then it is probably safe to say that the shuffling process is "random" for our purposes.

It may even be argued that the more "random" variables are included in the process, in the case of a b&m cardroom, the more the result of the process is "random." And thus perhaps b&m shuffling is a better simulation of randomness.

[Copernicus]

I mentioned this in another thread somewhere recently, but in statistical tests of the randomness of physical shuffles when only "riffle shuffles" (or whatever the proper name is) are used there is an optimum number of shuffles, any more or less and the distributions become less random. I believe the number was 5 or 7.

I also believe that the same studies resulted in the procedure that most if not all casinos require for poker, single deck and two deck blackjack, which is that there be a "wash" before the riffle shuffles. The wash was found to result in better randomness.

DS might have done some consulting in this area?

[Collin O'Mahon]

When you say "wash" you mean when the dealer spreads the cards out on the table and *cough* randomly moves them around?

[Copernicus]

Yes...I think "wash" is the proper term for that, but I'm sure there are dealers here who can correct that if I'm wrong.

[Wake up CALL]

[ QUOTE ]
I mentioned this in another thread somewhere recently, but in statistical tests of the randomness of physical shuffles when only "riffle shuffles" (or whatever the proper name is) are used there is an optimum number of shuffles, any more or less and the distributions become less random. I believe the number was 5 or 7.

I also believe that the same studies resulted in the procedure that most if not all casinos require for poker, single deck and two deck blackjack, which is that there be a "wash" before the riffle shuffles. The wash was found to result in better randomness.

DS might have done some consulting in this area?

[/ QUOTE ]

Copernicus, here are two good links for you about random card shuffling.

How Many Times to Shuffle

Perci Diaconis reference in Wikpedia

[Cyrus]

My impression is that poker players, as opposed to blackjack players, in general, are not familiar with shuffle routines and they are not interested in their secrets, either.