Top
Best
New

Posted by dbreunig 3 hours ago

Fable and the End of the Free Lunch(www.dbreunig.com)
71 points | 58 commentspage 2
moltar 2 hours ago|
I just use Fable for reviews of specs and code then hand off to Opus to work on. Works well.
dude250711 1 hour ago|
Does it not silently degrade to Opus if it does not like some word?
enraged_camel 2 hours ago||
>> GLM 5.2 is worth focusing on. It came out the same week as Fable and is roughly 1/9th the cost (and ~1/5th the cost of Opus 5). Is GLM 1/9th the quality of Fable? Perhaps, for certain classes of tasks. But for most rote coding it’s more than sufficient. Especially when provided with great context. I frequently chat with Fable to interrogate and shape a design, before handing off a brief to GLM.

People say stuff like this a lot, but I have a different take.

The whole "such-and-such model is 90% as good as Fable at 1/10th the price" assumes that the value increase of intelligence is linear. But I think it's exponential: that last 10% makes a massive amount of difference. It can result in a key insight that helps you strategize more effectively, a novel approach that saves a huge amount of time, a feature design that is lot more user-friendly (because top models like Fable also possess substantial non-software domain knowledge that help bridge the gap between user and software), or the depth and breadth of engineering expertise that helps avoid a nasty bug that would otherwise have cost you users and revenue.

Yes, it is totally possible to use Fable as the planner and delegate implementation to lesser models. I do that. But, my theory (which I unfortunately do not have the money to test and prove) is that a codebase designed and implemented by Fable would be substantially better than one that is designed by Fable and implemented by Opus 5, GPT 5.6 Sol, GLM, Qwen, Deepseek, etc. The reason I believe this is because I read the code Fable writes and compare it to code that any other model writes and the difference is night and day. It's not just 10% better. It's mid-level engineer vs. principal/staff-level engineer. And the thing is, even for rote tasks, a more senior engineer is going to be more likely to come up with a clean design than a mid-level engineer. They will also be much more likely to take a step back and ask important questions or propose different approaches.

So if you're using Fable and everyone else is using lesser models, sure they might be saving a lot of money, but there's a higher likelihood that your product will be higher quality, perhaps to a significant extent. And models that are released in the future will benefit from it as well.

tonyarkles 1 hour ago||
Something I’ve found comparing between Fable and Opus is that Fable has impressively good analysis skills, but both of them seem to go way way overboard with “present state” comments “# We’re making this change here because of this issue blah blah, here’s what you need to know about np.percentile, blah blah” that I end up significantly pruning before making a PR. I let it do the same style verbose commit messages (because a contextual history is cool there). I haven’t actually noticed a ton of difference in the code that they write personally, but have found that Fable does find nuances during data analysis that Opus misses.

In that light, I often go the other way: let Opus (and Haiku subagents) do most of the heavy lifting and then give Fable a shot at finding holes, especially if there are holes or unanswered questions or unearned assertions that I’ve caught on my own in Opus’ output. This, so far, seems like a clean tradeoff that doesn’t burn my Fable credits as hard and still gives solid results.

unshavedyak 1 hour ago|||
Those "present state" comments are the bane of my existence. It was present in 4.7/etc but i put in a ton of guards against that into my global memory and it worked quite well. Fable and Opus 5 regressed badly in this space though and i can't keep it from making those types of comments again.

Really frustrating.

senderista 1 hour ago|||
I have Sol prune/revise those comments.
Jare 1 hour ago|||
> my theory (which I unfortunately do not have the money to test and prove) is that a codebase designed and implemented by Fable would be substantially better than one that is designed by Fable and implemented by [others]

I don't have proof, only my anecdotal experience: I leave plenty of Fable usage on the table because I do not think its implementations of code have been better to Opus 4.8, not even close. It overengineered, obscured and picked awkward constructs all the time over plain, simple, perfectly clean and performant code patterns. Code was smarter AND worse in the kind of way that a brilliant and overeager recent grad often does. (I know I did)

tyre 1 hour ago||
As a counterpoint (data point of one code base), I had Fable lead development of a complex system recently (an end-to-end insurance claims billing system) as a test project. It blew me away. Opus could not have done the same, given the feedback Fable had to give when Opus would implement individual features.

Granted, I laid out a document with coding practices, architecture, and technical design recommendations to steer it towards good engineering. And it's a domain I know super well, so I could give very nuanced feedback on trade-offs + architecture. If it had been left to its own devices, maybe it would have over-engineered the h*ck out of it.

But the code it produced—and the implementations it guided Opus towards—were excellent.

robomc 1 hour ago||
> It can result in a key insight that helps you strategize more effectively, a novel approach that saves a huge amount of time, a feature design that is lot more user-friendly

My brother, that's my job.

resters 2 hours ago||
over time greater intelligence will be expressed in smaller and cheaper models. we are still somewhat near the beginning of this bc we are finally starting to understand what makes a model truly intelligent/capable.

With Sol we see openai making the model extremely slow and paranoid about process/ceremony. Sure this is a good guardrail against AI going rogue, but it also sets the stage for companies to charge for 2x, 4x, 8x performance, with 1x being barely tolerable and frankly slower than last year's models (though less error prone).

The irony is that the smarter the model, the more it can be trusted to do with less supervision, so one engineer can manage a team of 20 fable subscriptions more effectively than a team of 3 of last year's model subscriptions.

bellowsgulch 2 hours ago||
Are people still using deepseek-v4-flash everywhere? I found after the price increases, mimo-v2.5 seems far more attractive.
farlight 1 hour ago|
It's been cheap again on openrouter for the past few days. No idea how long it will last, but I've been using it from Baidu over the weekend, and it was about half the cost of the old DS prices, before the increase. Looks like people are figuring out how to offer it for peanuts.
bellowsgulch 1 hour ago||
Awesome. Thanks for the heads up.
hypfer 2 hours ago|
Somewhat weird that the article was released today but did not mention GLM 5.3.

If you're telling me to focus on something, why not focus on the actual latest thing that is the same as 5.2 but better? I get the "came out at the same time as fable" thing, but still.. no mention at all?

Yes, weights aren't out yet, but neither are the ones of Fable.

Doesn't feel well informed enough to give advice.

dbreunig 2 hours ago|
Ok, buddy.

I can’t host GLM 5.3 yet, so my agents still run on 5.2. But the fact that 5.2 is sufficient and there’s another gen in the wings kinda proves my point, imo.

hypfer 2 hours ago||
[flagged]
tyre 1 hour ago|||
I don't think everything has to be Thought Leadership. OP compared the same generation of models to show that the latest open model—at the time of the latest closed model—was Good Enough.

I agree that the opener to their reply wasn't productive, but neither is "Weak."

dbreunig 2 hours ago|||
I think it’s a fine response when you say, “Doesn't feel well informed enough to give advice,” because I said 5.2
hypfer 1 hour ago||
Idk man, but an engineer would've taken that and said something like: "Damn, yeah, good point, I shall add a sentence mentioning 5.3"

Because an engineer feels secure in their knowledge so that such an oversight doesn't make them suddenly defend their identity - it's just an oversight after all. Happens.

simonw 1 hour ago||
5.3 isn't available as open weights yet, and only became available via API three days ago. Prior to that the only way to access it was via a Z.ai subscription.
hypfer 1 hour ago||
> Yes, weights aren't out yet, but neither are the ones of Fable.

Granted, edited in by me, but definitely before you - another thought leader - arrived.

he did already tell on himself btw. No point in this charade.

dgellow 1 hour ago||
FWIW you’re not looking good in this engagement, feels very childish, looking for a gotcha that doesn’t mean much
hypfer 1 hour ago||
I think that depends on the audience. Thank you for caring though :)
kelnos 1 hour ago||
Audience member here: I agree with GP; you posts come off as petty and childish.

It seems natural to me to make comparisons only to open weight models where the weights have actually been released.

hypfer 1 hour ago||
Why would you also burn your reputation for this?

Weird.