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Can you be sure to clear a line at Tetris?

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Re: Can you be sure to clear a line at Tetris?

#11
post #2

Related: in the official specification of the game the pieces ("tetrominoes") are drawn from a bag to prevent the possibility of an unfavorable sequence of pieces that force you to lose the game. IIRC early implementations of the game did not always behave like that. https://tetris.fandom.com/wiki/Tetris_Guideline > You might have heard of the result that you can play forever with bag randomizer, Hold and 3 previews…

See also: https://news.ycombinator.com/item?id=20872110

"A history of Tetris randomizers (2018)"

Re: Can you be sure to clear a line at Tetris?

#12
post #2

Related: in the official specification of the game the pieces ("tetrominoes") are drawn from a bag to prevent the possibility of an unfavorable sequence of pieces that force you to lose the game. IIRC early implementations of the game did not always behave like that. https://tetris.fandom.com/wiki/Tetris_Guideline > You might have heard of the result that you can play forever with bag randomizer, Hold and 3 previews…

https://simon.lc/the-history-of-tetris-randomizers

Re: Can you be sure to clear a line at Tetris?

#13

There was a kid I knew in school who I would consider a very good tetris player. One time someone else was lamenting that they always get bad pieces and he said, "The Tetris gods will never give you a piece you can't play, you just don't know how to play it." Which has resonated with me for an oddly long time in my life.

This sort of thing comes up a lot in card games like mtg. Some players are convinced they're naturally unlucky. I like to phrase it as "bad decks get bad draws". To improve one has to be luck oblivious: improve what you can, accept what you can't. Bit of a serenity prayer approach

Re: Can you be sure to clear a line at Tetris?

#14
If you want to test a strategy against an adversarial tetris opponent: https://qntm.org/files/hatetris/hatetris.html

The method by which the AI selects the worst possible piece is extremely simple to describe (test all possible locations of all possible pieces, see which of the pieces' best-case scenarios is the worst, then spawn that worst piece), but quite time-consuming to execute, so please forgive me if your browser chugs a little after locking each piece. If you can figure out a way to accelerate the algorithm without diminishing its hate-filled efficiency, do let me know. The algorithm for "weighing" possibilities is to simply maximise the highest point of the "tower" after the piece is landed.

Re: Can you be sure to clear a line at Tetris?

#15
post #8

Is there a good way to reduce SAT or other decision problems to Tetris? Do we need to enlarge the grid to reduce larger problem instances, or can the duration of the play / length of the sequence be used for that? I would hope for something like "This list of clauses is satisfiable iff there is a winning strategy to clear at least N lines when given the following sequence of tetrominoes". (Where the article here says…

In my experience, strong human players can consistently keep track of random-bags and plan out holds, and do so at surprisingly high speeds. I'm not sure if a computer SAT-solver is needed to accomplish any of the tactics in Tetris-Guidelines. Maybe it'd be a fun exercise, like using SAT-solvers on human-level Sudoku puzzles. Or for maybe inventing "harder" versions of Tetris, designed for computer players instead of…

Most NP-complete problems have really good heuristics that come to within a hair of optimal on most useful real-world inputs, e.g. things like integer partitioning, bin packing, traveling salesman, etc. You need really unusual inputs to give an optimal solver a drastic advantage. Case in point, with real-world TSP the fact that the cities are embedded on a plane means their distances have constraints that don't exist in the general problem.

Re: Can you be sure to clear a line at Tetris?

#16

If you want to test a strategy against an adversarial tetris opponent: https://qntm.org/files/hatetris/hatetris.html The method by which the AI selects the worst possible piece is extremely simple to describe (test all possible locations of all possible pieces, see which of the pieces' best-case scenarios is the worst, then spawn that worst piece), but quite time-consuming to execute, so please forgive me if your bro…

The resulting algorithm seems to be "spawn z and s pieces on repeat". I only got one long piece and one L piece.

Re: Can you be sure to clear a line at Tetris?

#17

If you want to test a strategy against an adversarial tetris opponent: https://qntm.org/files/hatetris/hatetris.html The method by which the AI selects the worst possible piece is extremely simple to describe (test all possible locations of all possible pieces, see which of the pieces' best-case scenarios is the worst, then spawn that worst piece), but quite time-consuming to execute, so please forgive me if your bro…

I remember seeing this at one point and clearing a grand total of 5 lines in one game. Turns out it's hard if the game is trying to make you lose.

Re: Can you be sure to clear a line at Tetris?

#18

Yes in "Tetris Guidelines". In fact, greater feats can be accomplished in modern Tetris games, thanks to these strong guidelines. https://www.youtube.com/watch?v=qmG0NcbrLTE Strong players practice these loops all the time. Its possible thanks to the "bag randomizer". -------- The BT Cannon is a TSpin double (4 damage + B2B bonus) + TSpin Triple (6 damage + B2B bonus), for a total of 11 damage. The DT-cannon followup…

I think we had this discussion a year or two ago, but personally I find the guideline algorithm to be boring. It's definitely more oriented to PVP Tetris. Something like TGM would be boring if you can just execute builds instead of preparing your stack and play for just about anything.

It's true that there's a lot of different builds (I'm personally more partial to the albatross special than DT cannons) and builds are not only related to what you can build, also how you should respond to your opponent. Like, is the game even fun when you're just spamming t-spins with Tafokint's T-spin factory?

I'm a pretty highly ranked Tetris player, top ten in Finland in T99, Tetr.io and Puyo Puyo Tetris and somewhere in the top 100 as well, and in reality I think fancier builds like DT-cannons are too fragile and reliant on a clean-ish stack that they're not even viable in high level play. If you take ten seconds to set up a tetris or 15 seconds for a triple T-spin then you're gonna get spammed to death before you can reply with your fancy build.

In modern PVP Tetris I think there's only three tactics. If you're not too technical, you need be fast at tetrises and hope you can outpace your opponent.

If you're slower, you have to deal more damage in the same time or less = T-spins for double damage. It took me a year of practicing to intuitively start leaving t-spin doubles in more unconventional setups. There's the risk of being outpaced and spammed but the double damage mitigates it a bit.

Third option is comboing. I think it's the hardest to pull off but it's also the most effective. With a three wide hole it's fairly easy to get a combo going but there's always a huge risk of topping out by a badly timed attack from the opponent. Four wide is harder to keep going but it's safer.

Depending on the game and network code, combo builds can be game breaking and actually stagger the enemy so that they can't even reply to your attacks. It is however the least effective build in terms of how many pieces you need and the return damage for each clear and there's the most unknowns in how you're supposed to stack.

But to sum up in short, I don't think "builds" per se are the way to go in PVP. The "stack, attack and reply" formula simply leaves too large holes for your opponent to attack and it's not variable enough. Seeing parts of builds as patterns, like using a roof on a T-shaped hole to build a triple T-spin is useful if you can figure it out whilst clearing garbage and keeping a constant battering on your enemy going.

Personally, I think TTC forcing guidelines on single player games is boring. TGM TAP+ was the pinnacle in terms of game behavior and algorithms, IMO holds and the floor kicks in Terror Instinct made everything a bit too easy and all the difficulty comes from being ridiculously fast instead of being super meticulous and eloquent in your stacking.

Re: Can you be sure to clear a line at Tetris?

#19
post #8

Is there a good way to reduce SAT or other decision problems to Tetris? Do we need to enlarge the grid to reduce larger problem instances, or can the duration of the play / length of the sequence be used for that? I would hope for something like "This list of clauses is satisfiable iff there is a winning strategy to clear at least N lines when given the following sequence of tetrominoes". (Where the article here says…

Yes.

https://www.google.com/search?q=tetris%20n-p%20complete

Re: Can you be sure to clear a line at Tetris?

#20

If you want to test a strategy against an adversarial tetris opponent: https://qntm.org/files/hatetris/hatetris.html The method by which the AI selects the worst possible piece is extremely simple to describe (test all possible locations of all possible pieces, see which of the pieces' best-case scenarios is the worst, then spawn that worst piece), but quite time-consuming to execute, so please forgive me if your bro…

The resulting algorithm seems to be "spawn z and s pieces on repeat". I only got one long piece and one L piece.

The author may have written a brute force algorithm when a greedy solution would have worked :)
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