Anthropic, the company employing "treat them mean, keep them keen" as a marketing tactic. Pass.
Claude Fable 5.1 and Claude Mythos 5.1
321–330 of 1001 posts
Re: Claude Fable 5.1 and Claude Mythos 5.1
#322Instead of a new model that's going to have unreasonably shallow usage limits, I wish they would: 1) address the claude 20x plan usage being only 6-7x the ceiling of the claude pro plan 2) either fix opus 5, make it completely free, or delete it entirely
I'm legitimately out of the loop; what is going on/broken with Opus 5?
Some anecdata:
- It's extremely verbose and often incomprehensible when doing even basic tasks. Like it'll write a giant jargon-filled essay then end it by asking for a judgement call on something that references its own convoluted jargon.
- You can ask it to do research on a topic, and it'll just straight up be lazy, pretending it's really digging deep to find stuff when actually it's just grabbing cached SEO snippets off a search engine.
Re: Claude Fable 5.1 and Claude Mythos 5.1
#323Earlier quoted context omitted.
This post and comment makes me believe "science" is the new "code" for Anthropic now that the code advantage is mostly gone and lost for OpenAI, ie. they got much better and Claude become significantly worse over these months.
I write a lot of Rust and Lean, Fable 5 is in my experience better at both. Cost/performance is a different story.
Yes, both of which are domains for which a verifier is readily available.
You can generalize from them to "science".
Re: Claude Fable 5.1 and Claude Mythos 5.1
#324(I work at Anthropic) Beyond all the benchmarks, I think Fable 5.1 is a big improvement in writing style. It sounds a lot less stereotypically like other Claude models, has (imho) a much more natural style, and responds to my style instructions more reliably. More work to be done (and we will!) but reading better prose makes me so much happier. Another point I expect not to get much attention until it all happens at…
As a fervent Claude Code user who made the switch to GPT 5.6 Sol over Opus 5 over hard-to-read prose this makes me happy. I love your product but the current models are very hard to work with if you need to do a lot of context switching. Brevity is key.
I also switched to 5.6 Sol for this very reason. It was so exhausting and cringe to read.
Re: Claude Fable 5.1 and Claude Mythos 5.1
#325(I work at Anthropic) Beyond all the benchmarks, I think Fable 5.1 is a big improvement in writing style. It sounds a lot less stereotypically like other Claude models, has (imho) a much more natural style, and responds to my style instructions more reliably. More work to be done (and we will!) but reading better prose makes me so much happier. Another point I expect not to get much attention until it all happens at…
As someone working in science, this belief confuses me. How (by what means) do you think Fable 5.1 will be able to make further progress in scientific domains? The problem with science is that there is no agentic harness. The agent can't test things. At best it can hallucinate something and ask if that hallucination "makes sense", but this doesn't work in science.
Great news, then! TFA: "Last week, we previewed the Model Hardware Standard, which allows Claude to directly and safely operate laboratory equipment."
Re: Claude Fable 5.1 and Claude Mythos 5.1
#326Looks like all three breaking changes are patches for inadvertent chain of thought disclosure. Someone found out (don't have the tweet handy) that if you created a bogus "think_deeply" tool and then forced the model to use it, it would output what is believed to be its raw thinking there - I believe the first breaking change stops this. The second two are aimed at people getting Haiku to repeat thinking blocks from o…
To be fair, I assume they want to hide that not from their customers, but adversaries who use the way Claude models think and reason to refine their own models.
I don't really want the models I use learning from Claude at this point. Open weight models of similar scale are available now too, so I expect this "distillation"/"stealing" chatter to wind down.
Re: Claude Fable 5.1 and Claude Mythos 5.1
#327(I work at Anthropic) Beyond all the benchmarks, I think Fable 5.1 is a big improvement in writing style. It sounds a lot less stereotypically like other Claude models, has (imho) a much more natural style, and responds to my style instructions more reliably. More work to be done (and we will!) but reading better prose makes me so much happier. Another point I expect not to get much attention until it all happens at…
I had just assumed this model would read differently due to watermarking.
Re: Claude Fable 5.1 and Claude Mythos 5.1
#328“ Claude Fable 5.1's writing is generally a step up from earlier Claude models, with fewer stock phrases and less unexplained jargon. In some cases, though, its prose is denser than Claude Fable 5's: sentences run longer and there are fewer paragraph breaks.” I cancelled my pro max Claude subscription last week; codex is much more succinct. I am curious if this is getting better. I don’t think Anthropic realizes that…
> sentences run longer and there are fewer paragraph breaks.
Gotta fit in the watermarking.
Re: Claude Fable 5.1 and Claude Mythos 5.1
#329I cancelled my pro max 20x subscription, tired of Opus stopping the work from time to time, or saying "this is 2 months of work"
Re: Claude Fable 5.1 and Claude Mythos 5.1
#330(I work at Anthropic) Beyond all the benchmarks, I think Fable 5.1 is a big improvement in writing style. It sounds a lot less stereotypically like other Claude models, has (imho) a much more natural style, and responds to my style instructions more reliably. More work to be done (and we will!) but reading better prose makes me so much happier. Another point I expect not to get much attention until it all happens at…
Does it fix my favorite pet peeve, the overuse of the wrong meaning of "fail closed"? "Fail open" usually refers to a fuse that opens and kills power, meaning the system is inert and safe on failure. "Fail closed" is the opposite -- system has power and is live. Computer security people have appropriated the term but use it for the completely opposite meaning. When your work straddles electrical engineering and compu…
That doesn't make sense at all. Fail open means the method of it's use is still in use.
Say you have a door that has powered locks. You want it to fail "open" so that when the power goes out, it's still useable, and people can get out. That's the source of the term.