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The random draw for constructed deck is not very random?

PostPosted: 23 Jul 2011, 08:28
by lavino
Anyone found that the draw most of the time clustered card draw in a very narrow range? It doesn't happen all the time but I do notice that a lot of draw it tend to just draw the same cards within a very small range. For example if I have cardA x 4, cardB X4, cardC x4, cardD x4, cardE x4, cardF x4 cardG x4, cardH x 4, cardI x 4 and then 20 island. If is very likely to give me the followings (say 5 cards for test):

1) A, A, island, island, I
2) B, B, C, C, C
3) E, E, D, F, F

etc. Not saying it happens everytime and but I does seems that it is very likely to cluster the same cards and next to each other in some cases. Sometimes I have gone through redraw 3 times without a single land in all of them for a deck that has 22 mountains. It is until the 4th draw it finally gave me 2 mountain. I have played the a lot of real deck shuffle in the past I had some really had draw but never as bad as that. ^_^ If that is really bad luck it is really bad luck to me ;)

Re: The random draw for constructed deck is not very random?

PostPosted: 23 Jul 2011, 14:26
by Braids
have you run the deck analyzer within the deck builder? it should show you several sample opening hands.

22 mountains is a little low for a 60 card deck. may i suggest 24?

Re: The random draw for constructed deck is not very random?

PostPosted: 24 Jul 2011, 00:06
by UnderFlow
The problem is that most people have a wrong idea of what randomness is based on their offline experience. Shuffling offline is often not sufficiently random. I heard a rule of thumb of at least 7 riffle shuffles, but even that seems low to me, looking at the results (especially with cards sticking together etc). Thus you often have a more equal distibution of spells & land than when a computer does the shuffling (based on my experience using at least 3 different random hand generators). Computers are absolutely (pseudo-)random. </rant>
Anyway, I read complaints about the "broken" shufflers of MTGO and MWS and the developers' answers before and I am pretty sure that the shuffler of Forge is doing fine.

Re: The random draw for constructed deck is not very random?

PostPosted: 24 Jul 2011, 02:30
by Chris H.
I used to play the paper game at a local card store. I had a plastic battery operated card shuffling macine that did a great job of shuffling without wearing out my card colection.

But the machine did make quite a racket. :-$

Re: The random draw for constructed deck is not very random?

PostPosted: 24 Jul 2011, 02:50
by Braids
Chris H. wrote:I used to play the paper game at a local card store. I had a plastic battery operated card shuffling macine that did a great job of shuffling without wearing out my card colection.

But the machine did make quite a racket. :-$
really? wow. the only one i ever tried tended to slam my cards' opposing long edges against each other. and forget about using card sleeves with it.

Re: The random draw for constructed deck is not very random?

PostPosted: 24 Jul 2011, 04:07
by Rob Cashwalker
That's the great thing about using sleeves.. you can just mash groups of cards together.

The CardList object has a shuffle method, which actually executes 3 shuffle operations, based on the Collections object's shuffle method. That method iterates through each element and swaps each with another randomly selected element.

When Forge launches the game, it performs 6 Collections.shuffles, then does its own explicitly coded re-arrangement shuffle, then 6 more Collections.shuffles.

There's a card-trick - If you take a deck of regular playing cards and do 7 *perfect* shuffles, you get the deck back in the correct order. A perfect shuffle takes precisely half the deck and merges them 1 for 1. Most humans can't riffle shuffle perfectly, but some magicians have to do it for some tricks, so they practice a LOT, there was an episode of Timewarp where they did a slow-mo of shuffling, along with the art of bottom-dealing without noticing it in realtime.

Re: The random draw for constructed deck is not very random?

PostPosted: 26 Jul 2011, 17:28
by mtgrares
lavino wrote:Anyone found that the draw most of the time clustered card draw in a very narrow range? ... If that is really bad luck it is really bad luck to me ;)
Forge's shuffler is pretty simple but shuffles cards very randomly. Any "non-randomness" that you see is just random, strange but true. And yes computers are technically non-random and can only generate pseudo-random numbers but that only matters for encryption and security. For normal, everyday applications the computer generates random numbers just fine.

The computers internal random number generator might generate 10,000 numbers and then repeat so while it is isn't technical random, you'll never notice.