Gaming Tetris DS - blocks not equal distributed random?!?

[Jeda]

I recently got the urge to play some Tetris

, and after messing around with several flash games and NES emulators, I realized I never played the DS version before.

Now, it is obvious they reduced the difficulty of the classic mode as much as possible with those six preview stones, the block switching and the "I can think as long as I want as long as I rotate the block on the spot" thing. But did they actually go that extra step and made blocks no longer random?
Looking at the preview stones, I noticed there were never more than two of the same stonetypes among them. Not once during a 200 line marathon game., as if the game would look at the list of preview stones, and dice the new one only among those that are only available at most once.

I googled "Tetris DS" "not random" and came up with nothing, so am I seeing things or did I just miss the outcry I would expect from a non random Nintendo Tetris

 

[Zamo]

We can do a big experiment taking ~1000 players' block-falling patterns and analyze it if you want, or you can just enjoy tetris. You decide.

 

[Kimi]

Tetris isn't truly random in the first place. The method of picking the order of the bricks in done in blocks of seven.

You take one of each shape (I, J, L, O, S, T & Z) and then put them in a random order. You then take another set of each shape, but them in a random order. And repeat. So you'll always have sets of seven shapes each time, sometimes it's called the 'bag method'; you put all the items in a bag and keep taking one out until there's none left, at which point you put them all back in a start picking again.

Because of this, you'll never see more than two of the same shape at once on the previews. As you'll have to have the last shape in one set, then a full set, and the first shape in the third set. Which would take up 9 spaces (1+7+1) to see.



If you go out and play a Tetris version that's 100% random (as in doesn't use the bag method) the game is very different to play, anyone who plays a lot can see it as soon as you start playing as the distribution isn't evenly spread as it normally is. Even if you don't count the blocks as they drop down, you'll notice that you're still waiting for the I block which you should have got and end up loosing the game.

 

[Jeda]

Wow, that's even worse than I though.

Tetris isn't truly random in the first place.

You make it sound as if the bag method is the standart way to do it, but it for sure wasn't that way in the NES or Gameboy version... Any other "major" Tetris version that use that bag shuffeling?

QUOTEyou'll notice that you're still waiting for the I block which you should have got and end up loosing the game

Yes, that's Tetris for me. Your life in the hands of the almighty RNG

 

[m3rox]

Can't you just enjoy the game?

 

[Jeda]

Me asking questions about a rule change of my favorite puzzle game has not much to do with me enjoying the game.

That said, no I don't really enjoy Tetris DS, at least not the two Standart modes, as there is no challenge left.

 

[Kimi]

I'm almost 100% sure that the official rules on Tetris use the bag method to distributing the shapes, but I don't know when the rule was implemented. Looks like I'll have to do some investigating.


EDIT: The old GB and NES version don't use the bag method, they seem to be totally random. I've not done any real work on them, but they seem to be an equal distribution.

EDIT 2: The game for the GBA, Tetris Worlds, uses the bag method. And I'm now out of versions that I can look at to test.

 

[Jeda]

Thanks

Well from the flash games I played recently, none used the bag method. Gnometris is also not using bags

In fact, newer Tetris brand games from 2001 and later tend to follow a new guideline such that the randomizer generates all seven tetrominoes in a permutation at one time, guaranteeing an even distribution over the short term,[citation needed]

Oh look and I'm only 7 years out of date.

Then again, this tetris god here http://www.youtube.com/watch?v=jwC544Z37qo selects classic mode (other option is world mode) and then gets four "I" while only getting two z at the start, so I'd guess no bags here as well. His distribution does look lucky though.

 

[hova1]

http://www.tetrisconcept.com/wiki/index.php/Random_Generator
http://www.tetrisconcept.com/wiki/index.php/TGM_randomizer
there u go, if you want a better tetris for the DS try NDS_TGM, there was a thread here but it got deleted for reasons unknown

 

[Chrono_Tata]

Now, it is obvious they reduced the difficulty of the classic mode as much as possible with those six preview stones, the block switching and the "I can think as long as I want as long as I rotate the block on the spot" thing.

A bit off topic but I don't think they were making the game "easier" as such, but more like rebalancing the game. At higher difficulties, the blocks fall much faster than classic tetris so the changes are really needed if you want to survive. The six preview stones does seem a bit of an overkill. Do people really plan forward that far?

 

[Jeda]

At higher difficulties, the blocks fall much faster than classic tetris so the changes are really needed if you want to survive.

It kind of feels like the other way around. Infinite spin means speed doesn't really matter so they added more speed "because they could".

Yes it is redesign/rebalance of the rules but for me...well I finished 20-5 with only tetris so I'll go with "it's easier"

@hova1: Thanks for the links, very intresting wiki. I had no idea those crazy rotations were possible.. I'll try out NDS_TGM too