[HN Gopher] Show HN: TetrisBench - Gemini Flash reaches 66% win ...
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       Show HN: TetrisBench - Gemini Flash reaches 66% win rate on Tetris
       against Opus
        
       Author : ykhli
       Score  : 55 points
       Date   : 2026-01-26 18:42 UTC (4 hours ago)
        
 (HTM) web link (tetrisbench.com)
 (TXT) w3m dump (tetrisbench.com)
        
       | akomtu wrote:
       | It would be more interesting to make it build a chess engine and
       | compare it against Stockfish. The chess engine should be a
       | standalone no-dependencies C/C++ program that fits in NNN lines
       | of code.
        
         | gpm wrote:
         | Comparing against stockfish isn't fair. That's comparing
         | against enormous amounts of compute spent experimenting with
         | strategies, training neutral nets, etc.
         | 
         | It will lose so badly there will be no point in the comparison.
         | 
         | Besides you could compare models (and harnesses) directly
         | against eachother.
        
         | vunderba wrote:
         | My back-of-the-envelope guess would be that 99% of LLMs given
         | the task to build a chess engine would probably just end up
         | implementing a flavor of negamax and calling it a day.
         | 
         | https://en.wikipedia.org/wiki/Negamax
        
       | OGEnthusiast wrote:
       | Gemini 3 Flash is at a very nice point along the price-
       | performance curve. A good workhorse model, while supplementing it
       | with Opus 4.5 / Gemini 3 Pro for more complex tasks.
        
       | bubblesorting wrote:
       | Very cool! I am a good Tetris player (in the top 10% of players)
       | and wanted to give brick yeeting against an LLM a spin.
       | 
       | Some feedback: - Knowing the scoring system is helpful when going
       | 1v1 high score
       | 
       | - Use a different randomization system, I kept getting starved
       | for pieces like I. True random is fine, throwing a copy of every
       | piece into a bag and then drawing them one by one is better (7
       | bag), nearly random with some lookbehind to prevent getting a
       | string of ZSZS is solid, too (TGM randomizer)
       | 
       | - Piece rotation feels left-biased, and keeps making me mis-drop,
       | like the T pieces shift to the left if you spin 4 times. Check
       | out https://tetris.wiki/images/thumb/3/3d/SRS-
       | pieces.png/300px-S... or
       | https://tetris.wiki/images/b/b5/Tgm_basic_ars_description.pn...
       | for examples of how other games are doing it.
       | 
       | - Clockwise and counter-clockwise rotation is important for human
       | players, we can only hit so many keys per second
       | 
       | - re-mappable keys are also appreciated
       | 
       | Nice work, I'm going to keep watching.
        
         | qsort wrote:
         | The worst thing is that the delayed auto shift is slightly off
         | and it messes my finesse. (I used to play competitive tetris as
         | well, but between getting older -> worse reflexes and vision
         | problems I can't really play anymore. Weirdly, finesse muscle
         | memory is still working.)
         | 
         | I don't think the goal is to make a PvP simulator, it would be
         | too easy to cheese or do weird strategies. It's mostly for LLMs
         | to play.
        
           | bubblesorting wrote:
           | Hello fellow Tetris nerd with a -sort username :)
           | 
           | On the topic of reflexes decaying (I'm getting there, in my
           | late 30s): Have you played Stackflow? It's a number go up
           | roguelite disguised as an arcade brick stacking game, but the
           | gravity is low enough that it is effectively turn based. More
           | about 'deck' building, less about chaining PCs and C-Spins.
        
         | vunderba wrote:
         | I actually grew up playing the Spectrum HoloByte version of
         | Tetris for PC, which only lets you rotate in one direction. As
         | a result, I ended up playing NES Tetris for years as a kid
         | before realizing it lets you rotate clockwise /
         | counterclockwise!
         | 
         | https://en.wikipedia.org/wiki/Tetris_(Spectrum_HoloByte)
        
       | arendtio wrote:
       | There are some concepts clashing here.
       | 
       | I mean, if you let the LLM build a testris bot, it would be 1000x
       | better than what the LLMs are doing. So yes, it is fun to win
       | against an AI, but to be fair against such processing power, you
       | should not be able to win. It is only possible because LLMs are
       | not built for such tasks.
        
         | i_cannot_hack wrote:
         | Fun fact: Humans were not build for playing Tetris either!
        
         | westurner wrote:
         | Task: play tetris
         | 
         | Task: write and optimize a tetris bot
         | 
         | Task: write and safely online optimize a tetris bot with
         | consideration for cost to converge
         | 
         | openai/baselines (7 years ago) was leading on RL and then
         | AlphaZero and Self-Attention Transformer networks.
         | 
         | LLMs are trained with RL, but aren't general purpose game
         | theoretic RL agents?
        
       | burkaman wrote:
       | It's actually 80% against Opus, 66% average against the 5 models
       | it's tested with.
        
       | esafak wrote:
       | I imagine this is because Tetris is visual and the Gemini models
       | are strong visually.
        
         | bogtog wrote:
         | I figure OP would try and give the models pure text forms of
         | the game?
         | 
         | .....
         | 
         | l....
         | 
         | l....
         | 
         | l.ttt
         | 
         | l..t.
        
       | vunderba wrote:
       | Interesting but frustratingly vague on details. How exactly are
       | the models playing? Is it using some kind of PGN equivalent in
       | Tetris that represents a on-going game, passing an ASCII
       | representation, encoding as a JSON structure, or just directly
       | sending screenshots of the game to the various LLMs?
        
         | storystarling wrote:
         | It has to be turn-based. Even with Flash's speed, the inference
         | latency would kill you in a real-time loop. They're likely
         | pausing the game state after every tick to wait for the API
         | response before resuming.
        
         | ykhli wrote:
         | answered this in a comment above! It's not turn or visual
         | layout based since LLMs are not trained that way. The
         | representation is a JSON structure, but LLMs plug in algorithms
         | and keeps optimizing it as the game state evolves
        
           | vunderba wrote:
           | Thanks for the clarification! Kind of reminds me of the Brian
           | Moore's AI clocks which uses several LLMs to continuously
           | generate HTML/CSS to create an analog clock for comparisons.
           | 
           | https://clocks.brianmoore.com
        
       | tiahura wrote:
       | I'd like to see a nethackbench.
        
       | ykhli wrote:
       | Thanks for all the questions! More details on how this works:
       | 
       | - Each model starts with an initial optimization function for
       | evaluating Tetris moves.
       | 
       | - As the game progresses, the model sees the current board state
       | and updates its algorithm--adapting its strategy based on how the
       | game is evolving.
       | 
       | - The model continuously refines its optimizer. It decides when
       | it needs to re-evaluate and when it should implement the next
       | optimization function
       | 
       | - The model generates updated code, executes it to score all
       | placements, and picks the best move.
       | 
       | - The reason I reframed this problem to a coding problem is
       | Tetris is an optimization game in nature. At first I did try
       | asking LLMs where to place each piece at every turn but models
       | are just terrible at visual reasoning. What LLMs great at though
       | is coding.
        
       | p0w3n3d wrote:
       | Guys, I don't know how to tell you but... Tetris can web solved
       | without LLM...
        
       | purplecats wrote:
       | watch link?
        
       | segmondy wrote:
       | ... and what does this prove? what can you decide to use one LLM
       | to solve over another based on this tetrisbench besides play
       | tetris?
        
       | indigodaddy wrote:
       | Is there a tl;dr on why this is? Does it just make faster
       | decisions?
        
       | bityard wrote:
       | Looks fun, but I'm not willing to give out my email address just
       | to play a game.
       | 
       | Also, if the creator is reading this, you should know that Tetris
       | Holdings is extremely aggressive with their trademark
       | enforcement.
        
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       (page generated 2026-01-26 23:00 UTC)