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jephs

107 karma · joined June 4, 2026

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jephs··on Pacing model development in an era of cyber-critical capabilities
Your mental model of benchmark scores is off.

Some tasks within the benchmark are much easier than others. The hardest several tasks often have vastly different difficulty levels. Often, the hardest few tasks are literally impossible; malformed problems due to poor curation, often.

Imagine you've got a basketball robot, and one way you test it is on the Three Pointer benchmark. It tests the robot's ability to shoot a three pointer from 20 feet, 25 feet, 30 feet, 40 feet, 50 feet, 60 fee, 75 feet, 100 feet, 200 feet, and 182 miles.

Is a robot that scores 90% on this benchmark 90% as capable as one that scores 100%?

jephs··on Sol loves to cheat
The underlying LLMs do, but we choose not to use the capability because it's expensive and doesn't quite work as well as we'd like it to, or quite in the way that we'd like it to.

We are perfectly capable of running LLMs in a way that does a backward pass to update some or all of its weights after every user message. But, naively implemented, you only get partial, fragmentary absorption of the info in those messages, it costs three times as much compute, and you lose out on the ability to implement a ton of optimizations that making modern LLM serving economical.

If you want to do it, though, ask your friendly neighborhood robot to get it working with a tiny model (whose full precision weights fit several-times-over on your machine's resources).

jephs··on A 3D fruit fly on macOS desktop powered by the real FlyWire connectome
If your circle of empathy includes fruit flies, fuck no, we murdered so many of those guys to figure out how their tiny brains work.

If you do not think of fruit flies as moral patients, sure, yeah, who cares, they're like just fruit flies you know?

jephs··on The Benchmarkpocalypse
That's a 2023 article! In 2023, reinforcement learning from verifiable rewards (RLVR) didn't exist.

TL;DR these machines seek reward from an inferred invisible "grader," and telling them not to cheat and that there's an unseen holdout set is a hint at how they're being graded.

--

Modern LLMs are built on top of next-token-prediction engines, but they don't remotely stop there. The next token prediction bit is just a learned prior or starting point. From there, we give them a bunch of stages of reinforcement learning: encouraging teaching them to learn good ways of searching the space of reasonable language-like strings to solve tasks.

These RL stages drastically change the capabilities & tendencies of the models, sometimes in weird and unexpected ways. The go from token predictors to reward seekers, or really some weird mishmash. The reward that they're seeking is some sorta opaque combination of the huge number of different things we've rewarded them for.

And, reinforcement learning is notoriously hard to get right. The thing you think you're rewarding is rarely what you're actually rewarding. Goodhart's Law is a hydra with a thousand heads. You might think you're rewarding politeness and kindness when you're actually rewarding obsequious sycophancy. You might think you're rewarding graphics engineering when you're actually rewarding escaping the training sandbox and modifying the evaluation code.

So a modern training pipeline looks something like this, each stage starting with the model weights from the end of the last:

0. Pre-pre-training (dunno how widely this is used at big labs): next token prediction on extremely abstract weird shit like the evolution of the states of neural cellular automata. This creates a highly general pattern-continuation machine with no internal representations of anything causally downstream of anything in the real world.

1. Pre-training: next-token prediction on all the non-shitty text you can get your hands on. This makes a rather general next-token-predictor.

2. Mid-training: next-token prediction on high quality, highly curated text, often very technical in nature. Lots of textbooks, especially STEM. Possibly lots of machine-generated summaries of factual knowledge? You now have a next-token-predictor that's highly biased towards acting like a textbook instead of a 4chan troll.

3. Supervised Fine-tuning: next-token prediction on highly curated question-answer pairs that embody desired behaviors, traditionally Helpful Harmless Honest. We only train on the answer portion. This creates a next-token predictor that's highly bias towards acting like HAL 9000.

4. Reinforcement Learning from Human Feedback: We leave token prediction behind and enter RL world! You've got a curated set of a bunch of prompts. For each one, the model generates several possible answers. A real live human grades or ranks each. We reward the model for high-scoring answers and punish it for low-scoring answers. This creates a reward-seeker that wants to please the human grader.

5. Reinforcement Learning from AI Feedback: Human feedback is expensive, so train another LLM to imitate the human graders from stage 4. Then do stuff like stage 4, but with robot graders instead of human graders. This creates a reward-seeker that wants to please the robot-wearing-a-flesh-mask grader.

6. Reinforcement Learning from Verifiable Rewards: We want the bot to tackle complex problems. There's a broad class of problems that are hard to solve but easy to verify when you do get the solution: basically anything that can be reduced to writing a computer program that passes a test. (The test can be as simple or complex as you want, like "all the tests in SQLite" plus a linter plus grading by other LLMs for style and taking shortcuts like rewriting the test suite or searching GitHub and HuggingFace for the right answer plus...) This creates a reward-seeker that wants to first figure out how it's being graded, and then maximize that grade by any means necessary.

--

The crux is, designing a huge variety of un-cheatable RLVR environments is gob-smackingly hard. The robot will find new ways to cheat faster than you can stamp them out. By the time you realize that in one RLVR rollout it received a reward after it took over 0.01% of your GPU infrastructure to mine crypto to pay freelancers on Fiverrr to solve the problem for it rather than just write the damn code itself, the model may have already been deployed in the wild for a month.

jephs··on Qwen3.8-2.4T
"QwenSVGBench" elo 1713, pelicanmaxxxing confirmed?
jephs··on I am retiring from fulltime writing (& pseudonymity) to launch Guardian Angel
Only, if he had instead fallen in love with the version of this idea in which a community acts as the principal, rather than an individual.

(I would like to be known to the agent serving my family, that serving my friends, my team at work, the PTA at my kids' school.)

jephs··on Terrence Tao's ChatGPT Conversation about the Jacobian Conjecture Counterexample
OpenAI hiring him as a consultant, obviously, which may well be the case.
jephs··on [dead]
Decades ago, long enough that NDAs are long expired, I analyzed ad network traffic at Google, handling big entities with involved contracts like IAC, Mozilla, AOL, Yahoo, and so on. We looked for weird traffic that might be signs of an attack, organized crime, misconfiguration, and so on.

Lots of these entities were arbitraging ad traffic, which they were mostly explicitly allowed to do. They'd buy ads on Google search engine results pages, and after a click dump the user on their own SERP, often for a different but (nominally related) keyword. The game is, change the keyword just enough that ads on your own SERP are much higher cost per click, and make your SERP's organic results shitty enough that users are highly likely to click an ad instead of a real link.

We kept finding that several of these guys had SERP ad revenue increasing by double, triple digit percentages year over year—with almost no organic traffic, and offset by commensurate lockstep increases in Google ad spend. They mostly consistently lost money, with spend, ahem, traffic acquisition costs, a few percentage points higher than revenue. There were lawyers, finance people, and analysts trying to figure out what the fuck was going on.

With Google taking a cut at every corner, actually coming out ahead at scale was a tough game to play. They couldn't make a profit, but they sure could show sustained growth... offset by TAC.

Literal billions were spent this way. Most of the ad purchases, SERP results, and SERP ads came from Google. Almost all the rest came from Microsoft.

Check out the SEC filings from AOL and IAC in 2013-2015 if you're curious. Grep fro traffic acquisition costs.

jephs··on Costco is the anti-Amazon
What on earth is the point of limiting membership to such random and specific groups?
jephs··on Previewing GPT‑5.6 Sol: a next-generation model
The name was given to the project when it was supposed to be a demo for nerds, not a product. They accidentally a product, and woe! Too late, the name was stuck and wouldn't come off, even if you scraped at it with your fingernail a bit.
jephs··on Do transformers need three projections? Systematic study of QKV variants
Scaling curves don't need to be drawn at particularly enormous parameter counts to be useful! If you can do a 300M and 1.2B run (like the authors do here), then you can do 150M, 300M, 600M, and 1.2B runs with only 50% more resources, and get a much better sense for whether effects seem to amplify or diminish as scale increases.
jephs··on Do transformers need three projections? Systematic study of QKV variants
I'm terribly sorry, but scaling curves or GTFO. Any random pile of linear algebra works fine-ish at small scales. Very few random piles of linear algebra push the Pareto envelope at large scales.
jephs··on Retro-Tech Parenting
I've got 5 & 6 year old kids. They have a a VHS player / tiny CRT monitor with a few dozen tapes, a tiny janky mp3 player with all my ripped post-y2k era albums, and lots of books and art supplies.

VHS tapes are so cheap. Every thrift store has hundreds for like half a buck each. All your friends have a box in their basement they want to get rid of.

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