Memoryless randomizer - making tetrises

[jujube]

This guide is for making tetrises with a memoryless randomizer. The strategies are biased towards the scoring system in Gameboy Tetris and Tetris Friends -- Tetris 1989 (making tetrises is by far the best way to increase your score quickly), and towards playing in earlier levels where you have more time to think and improvise. Also I'm assuming people would prefer to lose a few games in the early levels while playing aggressively, giving themselves a good chance at setting a personal record score, instead of going for a good average score. Enjoy.


Watching the preview
It's always a good idea to know where you'll put the next piece before it spawns. This becomes more and more important in higher levels in Gameboy Tetris. But if you have time to improvise it helps a lot to watch the preview while the current piece is still falling. It's good to have a general area of the field where you want to put the falling piece, but to consider shifting it over a column from where you had originally planned, or rotating it a different way. It's better to make your stack ugly knowing you'll fix it with the next piece than to try to make it pretty all the time. This idea applies somewhat in all tetris games, but especially when the randomizer is memoryless.

The L piece can fit a few different ways here, so the preview can help you choose which way is best:
O coming next:


CONTINUED IN THE 2ND POST
(too many images)

Flexible planning
While you may be most comfortable building in columns 1-9 or 2-10 and tetrising by the wall, it's good to be flexible and find the easiest way to build without excessive skimming. Your entire game plan may change with each coming piece, especially when your stack is very low.

Here you have a low jagged stack and an L piece coming:


The L fits nicely in both of these places:


But the more you stack up in the center, the more you start depending on an ideal sequence of pieces to fill the sides. This isn't a big problem in games with more predictable randomizers, but when playing with memoryless you just don't know if you'll get the right pieces. Your best bet here would be to fill in the gap on the far right, and plan to tetris in either column 3 or 8:


Notice that now the stack can handle just about any sequence of pieces that may come. Even if you get a string of Z's, you can shift focus and work towards tetrising in column 10:


At this point you would probably want to fill in the left side, clear the third row from the bottom, and continue to build up columns 1-7 evenly until you can tetris in column 10. Eventually after tetrising once or twice and maybe skimming a bit, column 8 will open up and you should be able to tetris there. This is just an example, but the basic idea is to be prepared to tetris in any column when things don't go according to plan.

Overhangs
As a general rule it's a bad idea to make overhangs when playing with a memoryless randomizer, unless the very next piece will fill it. Even if one of several pieces can fill the hole you can't be certain you'll get any one of them soon. There are a few exceptions to this rule though. Here's one example:
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This twist setup is fine if you feel confident in your timing in Gameboy Tetris, and it's easy with lock delay in Tetris 1989:
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If the gravity is slow enough you can also push a T in from the side (or in Tetris 1989 approach the hole with the T rotated left once, then rotate it right twice after it lands):



Questions, comments and suggestions are appreciated. Thanks for reading.

[Zircean]

Nice article! Next time I boot up Super Tetris 3 I'll have to remember your skimming tips and what to do with a jagged stack. If I'm ever going to get close to Edo and CT in that game, I'm going to have to have a much better tetris efficiency D:

[jujube]

is the scoring system in Super Tetris 3 weighted like Gameboy Tetris?

GB Tetris rewards like this, where n is the points given for a single in a given level:
single: n
double: 1.25n per line
triple: 2.5n per line
tetris: 7.5n per line

and thanks.

oops, the 2nd pic has the wrong stack shape, and i can't edit and save the post because there are too many images  

oh well

[Rosti_LFC]

Good stuff. I'd say most of it is applicable regardless of randomiser.

[Blink]

very nice article jujube, i'm going to try this stuff in Tetris 1989

[jujube]

thanks everybody.

[clincher]

Really helpful I suck at memoryless randomizers i always stack relying on specific pieces comming soon

[jujube]

the best thing you can do is practice

[iphys]

In GB Tetris my preference is to separately stack in columns 1-4 and columns 6-10.  It makes it slightly harder having two separate stacks, but that way you can stack higher without fear of not being able to get your I piece into your tetris column when it comes.  Since the I pieces come at random, they'll tend to come in clusters rather than being evenly distributed, so it really pays if you can be set up to do at least two tetrises at a time, but since the pieces generate in rows 16/17 it's pretty deadly to stack any higher than row 12.

[jujube]

that's interesting iphys. would you say an optimal tetris stacking strategy would be to first leave a column open on the side, then to make a transition to tetrising in the middle when you get into higher levels? if so, around which level would most people have to make the transition? or would it be easier for a lot of people to leave the middle open the whole game when starting from level 9? i might have to expand this article.

[iphys]

If you were going to start out tetrising on the side, I would try to switch before you get to level 10 and the speed starts changing on you.  I usually try to do it starting from level 9.  Even at the slower speeds I feel more comfortable stacking higher with a central empty column, so it seems to result in more tetrises and fewer wasted I pieces.  At the higher levels, I feel more comfortable stacking even for just one tetris with that configuration, because I know it will be hard to get an I to the side column once you're in the high teen levels.  The other thing is a tetris is worth as much as 30 singles, and I know once I get to 170 lines the odds of my lasting beyond 200 are slim even if I just play it safe and take singles, so I usually take the chance of trying to sneak in a couple last tetrises even if it means dying before 180 lines.

There's also a whole logic to how to stack when you aren't yet built up to the level to be ready to tetris.  For instance, in your "I coming next" example my instinct would be to put the L on its back in case the third piece was an I as well so that I could put the I in column 8 and then score a tetris -- I hate it when I waste a sequence of I's where I could have scored a tetris and then I end up stacking with no I's coming and eventually being forced to take a bunch of singles.

[jujube]

If you were going to start out tetrising on the side, I would try to switch before you get to level 10 and the speed starts changing on you.  I usually try to do it starting from level 9.  Even at the slower speeds I feel more comfortable stacking higher with a central empty column, so it seems to result in more tetrises and fewer wasted I pieces.  At the higher levels, I feel more comfortable stacking even for just one tetris with that configuration, because I know it will be hard to get an I to the side column once you're in the high teen levels.  The other thing is a tetris is worth as much as 30 singles, and I know once I get to 170 lines the odds of my lasting beyond 200 are slim even if I just play it safe and take singles, so I usually take the chance of trying to sneak in a couple last tetrises even if it means dying before 180 lines.

good advice. would you want to make a guide on playing at higher levels?

[!--quoteo--][div class=\\\'quotetop\\\']QUOTE[/div][div class=\\\'quotemain\\\'][!--quotec--]
There's also a whole logic to how to stack when you aren't yet built up to the level to be ready to tetris.  For instance, in your "I coming next" example my instinct would be to put the L on its back in case the third piece was an I as well so that I could put the I in column 8 and then score a tetris -- I hate it when I waste a sequence of I's where I could have scored a tetris and then I end up stacking with no I's coming and eventually being forced to take a bunch of singles.
[/quote]
true, that would have worked too, and the left side of the stack still would have been receptive to most combinations of pieces.