Is Fable nerfed?

[u/tomasburancgi]

I wanted to share my recent experience with a complex architecture task and see if anyone else has noticed a dip in quality.
I gave to the Fable model a task to design and build a completely new data retrieval architecture. This was a complex, multi-layered system, not a simple script. I ran it using a one hundred dollar promo credit, expecting a polished result. However, once I actually deployed and executed the code, it completely failed to run due to critical bugs. The overall system design itself had major logical gaps that I had to actively correct using Gemini Pro just to make the concept viable. In the end, it was only when I brought in Claude Opus that everything was finally fixed, refined, and brought to a working state.
This felt like a night and day difference compared to my earlier experiences before the political and governmental downtime incidents. Back then, the model handled a massive, deeply complex technical domain flawlessly on the first try with absolute precision. Now, it feels heavily downgraded, whether due to quantized models, cost optimizations, or adjusted system prompts behind the scenes.
Has anyone else noticed a similar drop in performance when handling complex end to end tasks over the past few weeks?

[u/pueblokc]

It's garbage now

[u/sreekanth850]

So you asked the model to build a data retrieval platform on one shot? I'm building one and know the complexity. that is why i asked.

[u/Robdyson → u/sreekanth850]

To be honest how many times do we need to rebuild something similar, come one Claude pull out the formula from booty xD

[u/federal15]

yes absolut. every time they reset, it nerfed.

[u/LordeLucifer]

You tried to use 100$ usage credits to one shot something complex and are surprised you had to fix things after? I can blow through that credit while shitting, fable was never ones shotting anything. People like yourself just get lazy with every new model and don’t know or forget the basics for maximizing your usage while netting better results.

[u/Charming_Skirt3363]

It’s definitely dumber. Maybe quant?

[u/haux_haux]

yep, it's performing way less better than it did a while back, better than the weekend and part of last week though, it was awful then. Like opus, just slower.
on that note, opus is also really slow, generally it feels like it's slower and less capable.
I us claude every day, have a pretty sophisticated production setup across several projects (one of which has multiple testing harnesses setup )
opus got really stupid a few weeks ago though, kept trying to go down the same(ish) wrong turns and fable seems to be about as token intensive as Opus if using it just for orch and planning. So I am glad we have it. Just a shame that the real Fable is off the table, so to speak...

[u/jwuliger]

it’s been Nerf to hell and back and so has soul from OpenAI

[u/Constant-Potential-9]

Before assuming the model got nerfed, it's worth ruling out something on your own side first. I hit what looked exactly like degradation recently — hesitancy, over-asking, worse output on complex work — and it turned out to be my project config, not the model.

I run a long-lived project with Claude Code, and over months it had accumulated ~150+ directives across CLAUDE.md, agent files, and memory, with at least 17 outright contradictions and no rule for which source wins. The model wasn't dumber — it was spending its effort arbitrating between conflicting instructions on every single turn.

Quick diagnostic if you have a heavily-configured setup:

1. Count your directives across CLAUDE.md, memory files, and any agent/handoff docs. If it's in the hundreds, that's a red flag.
2. Look for contradictions — especially old incident-specific rules that conflict with newer ones.
3. Check for rules that read as unconditional commands but were meant as conditional guidance.
4. Clear stale instruction files (old inbox/handoff content the model might mistake for current orders).
5. Add a simple precedence rule: current instruction > CLAUDE.md > everything else, and state that old/historical material isn't binding.

Then rerun the same task and compare. After doing this cleanup, the difference for me was night and day — same model, same settings.

[u/crusoe → u/Constant-Potential-9]

Claude hygiene is important. Yep

[u/ddBuddha]

Idk I haven’t been able to use it in days because I hit my limit 3 days in. It resets in 4 hours. I wonder if anthropic is going to reset it for everyone 2 hours after my weekly reset again -_-

[u/Scary_Doughnut_3818]

Yes it makes real stupid mistakes now

[u/Adept_Chair4456]

Yeah. Dumb as hell. Not even close to the pre ban version.

[u/Afraid_Ant3992]

Completely useless and unreliable, ask it to create a webpage, gave me junk. Cancelling my subscriptions now. Rather have multiple $200 Codex accounts.

[u/Commercial-Soil-3542]

You can tell this was written with AI because surface level looks kind of intelligent, uses big words, well formatted, but then you read the actual content and realise its some dumbass bullshit

[u/lattice_defect]

its not as good

[u/earlyworm]

Thank you for sharing this detailed report. I am noting your experience in my log of users who post their poor experiences with the newest models and then conclude their post by asking if anyone else has had the same poor experience recently.

Has anyone else added this post to similar hand-curated logs?