5 ms·

Ah, as long as the generator of pieces has a couple properties, this will always work. I find this interesting, mostly because if the generation of pieces is tr

Ah, as long as the generator of pieces has a couple properties, this will always work. I find this interesting, mostly because if the generation of pieces is truly random, eventually you will lose; a sufficiently long alternation of S and Z tetrominoes cannot cleanly tessellate.

sp332 13y ago
FTA: Because the random generator provides strings of bags containing each of the 7 pieces in a random order, it is possible to construct a strategy around the relatively small variation, with looping patterns. There is also a variant of Tetris called Bastet, which always gives you the most unhelpful possible piece :)
- nthitz 13y ago
  Bastet: http://blahg.res0l.net/2009/01/bastet-bastard-tetris/ http://blahg.res0l.net/2009/01/bastet-bastard-tetris/ (HN user RobotCaleb created this Flash port!) and slightly more twisted Hatetris http://qntm.org/files/hatetris/hatetris.html http://qntm.org/files/hatetris/hatetris.html
- nazgulnarsil 13y ago
  isn't the most unhelpful piece always just s-z alternating?
  - needle0 13y ago
    Not always. When the well consists of mountains and valleys perfect for fitting S/Zs into, Bastet will deal you an O (square). Though it is possible to get the best of Bastet: its algorithm for determining the worst possible piece works by attempting to drop every piece straight down from all possible horizontal positions, and does not take sliding maneuvers into consideration. Taking advantage of this, you can create a large overhang at the top of the well, then play by building the majority of your stack under it.
munificent 13y ago
> I find this interesting, mostly because if the generation of pieces is truly random, eventually you will lose That's correct, but Tetris specifies that pieces are not chosen using a sequence of random pieces selected with equal probability. Instead, it uses "selection without replacement". Think of it as you get one of each piece and stuff them in a bag. Pull a piece from the bag. That's the next piece. Do not put it back in (hence "without replacement"). Repeat until the bag is empty then refill the bag.

sp332 13y ago

FTA: Because the random generator provides strings of bags containing each of the 7 pieces in a random order, it is possible to construct a strategy around the relatively small variation, with looping patterns. There is also a variant of Tetris called Bastet, which always gives you the most unhelpful possible piece :)

nthitz 13y ago
Bastet: http://blahg.res0l.net/2009/01/bastet-bastard-tetris/ http://blahg.res0l.net/2009/01/bastet-bastard-tetris/ (HN user RobotCaleb created this Flash port!) and slightly more twisted Hatetris http://qntm.org/files/hatetris/hatetris.html http://qntm.org/files/hatetris/hatetris.html
nazgulnarsil 13y ago
isn't the most unhelpful piece always just s-z alternating?
- needle0 13y ago
  Not always. When the well consists of mountains and valleys perfect for fitting S/Zs into, Bastet will deal you an O (square). Though it is possible to get the best of Bastet: its algorithm for determining the worst possible piece works by attempting to drop every piece straight down from all possible horizontal positions, and does not take sliding maneuvers into consideration. Taking advantage of this, you can create a large overhang at the top of the well, then play by building the majority of your stack under it.

munificent 13y ago

> I find this interesting, mostly because if the generation of pieces is truly random, eventually you will lose That's correct, but Tetris specifies that pieces are not chosen using a sequence of random pieces selected with equal probability. Instead, it uses "selection without replacement". Think of it as you get one of each piece and stuff them in a bag. Pull a piece from the bag. That's the next piece. Do not put it back in (hence "without replacement"). Repeat until the bag is empty then refill the bag.