alt Hacker NewsShow HN: A Claude Code skill to analyze your chess games
Hello HN,
It started as an experiment: can Claude play chess properly if it uses vision instead of PGN notation? Somehow it can.
The next experiment was to see whether Claude + Stockfish could explain a game. Somehow it can too.
A few sessions later, I had a system that takes my live audio notes (or text, for that matter) and a vague instruction like "analyze my last lichess game", and gives me a commented video of the game. The result is not perfect and it takes time to deliver (an hour or so), but for me it is a much more pleasant and memorable experience than clicking around Stockfish branches. It burns tokens, so make sure you have enough quota. From the session logs, the last analyzed game would have cost around $15 at API prices.
The fact that it reflects on my own thinking during the game makes it interesting from a teaching point of view, so I thought it was worth sharing.
Comments
Does this give sensible analysis if you don't record your thinking out loud?
I've been using Elogram (https://elogram.gg/, made by a friend), which gives interpretability by showing how difficulty of a position changes with elo.
As a chess player I feel this is fascinating although there are plenty of analysis options already on lichess on chess.com. Still, sometimes it is more about learning and curiosity. Well done.
Just a note that this is not novel. Automatic analysis of chess games built on traditional engines has existed for a long time. Without using stockfish as a sidekick, this wouldn’t be interesting because of the poor play of LLMs, however having an LLM enhance the commentary is interesting and I suspect has already been done by chess.com for years.
You could also download my free chess app that hooks up to Claude for real time game analysis or chat about the game. https://pwalessi.itch.io/chess-buddy
You say chess and I’m here to shamelessly promote my “coin chess” version:)
Nice use of a skill for something concrete. I've been happier with AI helpers that spit out a short, checkable report than ones that try to be a whole coach.
You only need to spend a couple of minutes talking to an LLM about chess to realize it has no understanding of the game. It will produce reasonable sounding explanations for things that are completely wrong. It will make illegal moves. It will hallucinate pieces on squares even when the entire PGN is in the context. There are no prompts you can give it to fix this. I don't really understand how you could create this skill without noticing this.
How does it work? Does it just use stockfish under the hood? I just remember the times when I tried to use an AI model to play chess and half of the time it either hung a piece or made an illegal move.
Very cool work!
Did you write the skills (text, and code) all by hand, or are those prompt outputs?
I am very interested in this, but it looks like the video link gives 404
Neat! I've been slopping together various games to have AI play them, balatro, poker, blackjack, it's just so fun. Was just thinking about chess, wondering if, if I gave them an unrestricted sandbox, they'd start using existing solvers or not. They're surprisingly good at doing cardcounting, by the way.
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Writing skills files like this one don't seem to be the future of computing or AI, not by the quality, nor by the cost (15$ per usage?).
Also, you seem to have written the actual SKILL.md prompts themselves with AI? I don't know what to say that's insane, at least write the prompts? This idea of asking chatgpt to write the prompts for you is beyond lazy. Then presenting it as a project or tool of value to share to others is delusional.
Sorry for being harsh
"The result is not perfect" as LLMs are
"The fact that it reflects on my own thinking during the game makes it interesting from a teaching point of view, so I thought it was worth sharing." As AI the premium sycophantic scammer does
"but for me it is a much more pleasant and memorable experience than clicking around Stockfish branches"
And SO much less effective than doing the harder, more tedious feeling work
The elo of opus 5 models is 1300 or so. I wouldn't take chess lessons from a 1300.
Already a year ago I vibe coded Babelfish: https://github.com/bobjansen/Babelfish
It integrates an LLM of your choice with StockFish to analyze games. Back then, the results weren't very good and I abandoned the project but a lot has changed (the LLM's got better and I did too) so maybe it is time to take another stab at it.