jmills
Joined: Sep 16, 2014
• Posts: 92
September 1st, 2015 at 7:39:43 AM permalink
I have a few questions I hope someone can answer about video poker machines. I know the random number generator determines what cards come out, but:

1. Does the RNG affect both the deal and the draw?

2. How fast does the RNG run? Does a half second pause affect what cards come out?

3. Is the RNG running constantly? If I sat at that machine 5 minutes earlier, would the first cards be the same as they are now?

Thanks.
teliot
Joined: Oct 19, 2009
• Posts: 1956
September 1st, 2015 at 7:56:04 AM permalink
Quote: jmills

1. Does the RNG affect both the deal and the draw?

2. How fast does the RNG run? Does a half second pause affect what cards come out?

3. Is the RNG running constantly? If I sat at that machine 5 minutes earlier, would the first cards be the same as they are now?
.

#1. Yes.

#2. Most modern RNG's can produce millions of random numbers per second. I just tested -- 100M random numbers took 18 seconds.

#3. Most RNGs are seeded once when the program boots, based on some environmental condition. After that, the RNG produces the next value based on its current state, which doesn't change until the next number is delivered.
ThatDonGuy
Joined: Jun 22, 2011
• Posts: 4017
September 1st, 2015 at 9:27:26 AM permalink
Quote: jmills

2. How fast does the RNG run? Does a half second pause affect what cards come out?

As teliot said, it generates millions of numbers per second.

Quote: jmills

3. Is the RNG running constantly?

Yes - otherwise it is far too easy for somebody to find a way to beat it. If 10 million numbers are generated each second, then even if your hand was moving at three times the speed of sound, it would move only about 1 mm in the time it would take to generate the next number.

Also note that the numbers are not generated in any particular single "loop" - that is, if a number from 1 to 1,000,000,000 is being generated, then the number 123,456,789 will not necessarily appear once in any 1,000,000,000 consecutive random numbers. This may have been how it was done decades ago - in fact, when i was in college in 1982, I created an electronic dice roller that rolled two six-sided dice by generating the pairs 1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 2-1, 2-2. ..., 6-5, 6-6 in order over and over again at a rate of 1 million pairs per second - but somebody figured out that if you can figure out how frequently the "jackpot number" comes up, you can reduce the probability of hitting it to around 1 in 10,000, which, for a \$1 slot machine with a \$500,000 jackpot, is a serious advantage play.
Dieter
Joined: Jul 23, 2014
• Posts: 1482
September 1st, 2015 at 3:14:18 PM permalink
Quote: jmills

Does a half second pause affect what cards come out?

Yes, but you (probably) have no way of selecting a particular draw.

Think of it like this: the dealer is shuffling, and then shuffles again, and then shuffles again, until you say stop. The dealer is shuffling 1000 times a second.
May the cards fall in your favor.
mustangsally
Joined: Mar 29, 2011
• Posts: 2463
September 1st, 2015 at 7:38:42 PM permalink
Quote: Dieter

Think of it like this: the dealer is shuffling, and then shuffles again, and then shuffles again, until you say stop. The dealer is shuffling 1000 times a second.

is there proof of this?

if the game was played on a table
and we walked up to the empty table to play, the dealer would not be shuffling the deck over and over.
in a shuffle machine it would be a waste of electricity

i think it is the same in a vp machine
online vp games where the code can be seen, like in javascript, the deck is not being shuffled many times per second

so i refuse to believe it is done that way in a vp machine

Sally
I Heart Vi Hart
98Clubs
Joined: Jun 3, 2010
• Posts: 1728
September 1st, 2015 at 8:52:23 PM permalink
But, when the initial 5-card hand is called, and dealt, does the machine continue to shuffle the remainder. or is the deck "frozen" as a real deck?

In fact I envision the deck being shuffled in between the cards dealt, and never stops shuffling until A.) the hand is over, after a draw, or B.) if all 5 cards are held.

Some people need to reimagine their thinking.
RS
Joined: Feb 11, 2014
• Posts: 8623
September 1st, 2015 at 10:10:54 PM permalink
I agree with sally on this one. Would be sufficient to shuffle once when DEAL is pressed, load 10 cards into memory, use the first 5 on the deal, and use the second 5 on the draw when applicable.

But I also don't know how it works in machines. But I know constantly shuffling doesn't make sense, both between deals and between draws.
Dieter
Joined: Jul 23, 2014
• Posts: 1482
September 1st, 2015 at 10:49:24 PM permalink
Quote: mustangsally

so i refuse to believe it is done that way in a vp machine

In order to be GLI certified, yes. GLI-11, section 3.3.4 says
Quote:

The RNG shall be cycled continuously in the background between games and during game play at a speed that cannot be timed by the player.

Not shuffling after the deal might make the game vulnerable to a next-card information attack.

Not continuously shuffling might make the game more vulnerable to some sort of next-card information attack.

So, I see three scenarios:
- Shuffle before the deal, and then the deck is played out.
- Shuffle before the deal, and then shuffle before the draw.
- Shuffle the remaining deck constantly.

One of these is more secure than the others.

In any case the original question was "does a half second pause affect what cards come out?"
And I believe that's a yes, since a different RNG sequence would be selected, and the shuffle is based on the RNG.

... Just like I fully expect that hitting the spin button on a slot machine at a different moment selects a different
RNG stream and that gets you a different result. (But they all average together.)

Now, in a shuffle machine, there is a negligible chance of figuring out the order of the cards when they're closed away in that black box hanging off the table. That's not necessarily the case with passively reading computer memory.

It's not directly van Eck phreaking, but computer buses do make noise, and they could be intelligible (although security will wonder why you brought your suitcase down to keep you company while you play video poker).
May the cards fall in your favor.
charliepatrick
Joined: Jun 17, 2011
• Posts: 1949
September 2nd, 2015 at 7:28:33 AM permalink
This only applies to the UK, but I vaguely remember reading something about the random number generators having to continue to pick random numbers in the background. Otherwise it might be possible to see where in the, admittedly large, loop the machine was and work out the next draw. It doesn't take much work for a computer to continue to do this, say every 1/100th second.

It's also fairly easy to shuffle the deck as only needs 51 (or number of cards in shoe-1) random numbers. The computer only slows down when it runs out of numbers from the current state and needs to generate more - but again that doesn't take long and is part of the get-next-random-number routine.

When "Deal" is pressed, play the hand out (as one would probably have to keep a copy of the deck for debugging purposes or verification, I wouldn't re-shuffle prior to draw part).
DoubleOrNothing
Joined: Jan 2, 2012
• Posts: 186
September 2nd, 2015 at 9:06:49 AM permalink
Quote: RS

But I know constantly shuffling doesn't make sense, both between deals and between draws.

What real difference, all the shuffling, if what's going to happen happens anyway?

The only way that real life is randomized is if the fields are moving alongside the moving energies in the same way. If wormholes in space-time are always present. If we could not only see the universe from outside, but also reach in and rearrange it.

Only the One, the great mover, who is also the "road" can be in such constant flux.
I can't believe what I believe.