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What Smarter Models Make Obsolete

A new frontier model has shipped almost every week this fall. If the next ones are much smarter, which of today’s habits still pay off? I tested five common techniques on a small, a mid-size and a top model. The prompt tricks faded. The tools and checks didn’t.

The problem

Most AI best practice was written for weaker models: long instructions, expert personas, worked examples, “think step by step.” Teams have built libraries of prompts around them, and new hires learn them as craft.

Meanwhile the frontier keeps moving. In September alone, OpenAI, Anthropic and Google each shipped or announced a new top model. If those tricks were compensating for weak models, they are about to become dead weight, and the effort spent on them should go somewhere that lasts.

13 of 18benchmarks Google says Gemini 4 Argon leads, announced September 30 and so far open only to vetted cyber defenders
$4 / $20per million tokens for Claude Opus 5.5, cheaper than the Opus 5 it replaced and on par with Fable 5.1 on most work
4 weeksfor GPT-6 Astra, Claude Fable 5.1, Opus 5.5 and Gemini 4 Argon all to arrive, September 1 to 30, 2026

You can’t test tomorrow’s model today. But you can test today’s small, middle and top models side by side, and see which techniques lose value as intelligence rises. That trend is the best forecast available.

How I measure the problem
  1. Right answers for each technique at each model size, on fresh problems graded by code
  2. Cost per right answer, because a technique that adds tokens but not accuracy is a tax
  3. The trend from small to large, a technique whose benefit shrinks with size is scaffolding
Why I chose it

Every build on this site leaned on some technique: calibration, quote checks, decision models, thinking levels. Before the next generation of models arrives, I wanted to know which of those habits are investments and which are crutches.

The ideaUse model size as a time machine. Whatever stops helping the top model today will stop helping every model soon. Put effort into what still helps at the top: tools, verification and good tests.

Sources are listed at the end of the page.

Five techniques, three model sizes

The same 16 problems in every cell, all at reasoning effort “low.” Pick a measure, then a cell to see which problems it got right.

Right–
Cost per right answer–
Output tokensaverage per problem–


    

Prompt tricks didn’t help, at any size

Examples changed jobs

Tools turn a small model into a big one

Log scale. Each bar is the cost of one right answer, at published prices (Astra at the flex tier).

The frontier, as of October 10, 2026

What is actually shipped, with prices, and what is only rumored. Benchmarks are the vendors’ own unless noted.

ModelReleasedPrice per 1M tokens (in / out)Notes
Gemini 4 ArgonAnnounced Sep 30$2 / $10 introductory, then $4 / $20Leads 13 of 18 benchmarks Google disclosed, such as GraphWalks long context 84.2% against Astra’s 71.8%; trails on some coding and terminal tests. First on Vals Index (68.9%). Access limited to vetted cyber defenders for now.
Claude Opus 5.5Sep 23$4 / $20Terminal-Bench 4.0 66.4%, OSWorld 2.0 81.8%. Thinking always on, medium by default. Performs at Fable 5.1’s level on most work.
GPT-6 Sol and LunaSep 22$2 / $10 and $0.10 / $0.50The mid and small GPT-6 models used here.
GPT-6 AstraSep 3$10 / $50OpenAI’s top model, used here at the half-price flex tier.
Claude Fable 5.1Sep 1$10 / $50Anthropic’s most capable generally available model; same model as Mythos 5.1, which has lighter safeguards for vetted organizations. Humanity’s Last Exam 65.0% with tools.
Rumored, not announced

Anthropic“Fable 5.5” is a community name. As of October 5, Anthropic had announced no Fable 5.5 or 6, date or model ID.

OpenAINothing about a successor to GPT-6 is confirmed. A “Bel” pretraining leak from August is unverified; one analysis estimates a GPT-7 in the second half of 2027 at the earliest plausible pace.

GoogleArgon is announced and benchmarked but not broadly available, so independent tests are still to come.

What to invest in

Sorted by the evidence on this page and the builds before it. “Fades” means its benefit shrank or vanished as models got stronger.

FadesHelped weak models; little or nothing now

  • Measured hereLong expert prompts and personasNever beat a plain request; cost up to 27% more on the top model.
  • Measured here“Think step by step”Reasoning models already think. The instruction added tokens and, on the small model, errors.
  • Measured in Second OpinionAsking the same thing several waysRephrasing added noise instead of signal, and in How Sure Is Sure? rewording flipped one decision in five.
  • Measured in How Hard Should It Think?Turning the thinking dial to maxSame score as medium at about 4× the cost per right answer.

LastsHelped at every size, or matters more as models improve

  • Measured hereTools: let code do the exact work16 of 16 at every size, with the fewest tokens.
  • Measured in Second OpinionVerification against the sourceMaking answers quote the contract beat a bigger model at an eighth of the cost.
  • Measured in every buildYour own test setCalibration on labeled data was the biggest single gain in Second Opinion, and every result here came from a graded set.
  • Measured hereExamples as a format contractNo longer teaching, but they cut output by about 40% on the mid-size and top models.

What it means for the people

The skill shifts from coaxing a model to specifying, equipping and checking it.

Prompt craft becomes spec writingThe prompt gets shorter and the goal gets sharper: what done looks like, what it may touch, how it will be checked.
Engineers build tools, not workaroundsCalculators, code runners, search and verified lookups give every model size the same reliable hands.
Domain experts write the testsA graded set of real cases is what lets a team adopt next month’s model in an afternoon instead of a quarter.
What disappears, and what doesn’t

Prompt libraries tuned to one model’s quirks lose value with each release. Knowing what good looks like, owning the tests that prove it, and deciding what a model may do on its own become the core of the job.

Try it

Check the practices your team relies on today.

Likely to fade0
Likely to last0

Check a few practices to see where your effort is going.

How it works

16 fresh problemsBusiness days, shortest routes, seating logic and counting, generated today from a seed, with answers computed by code.
Five techniquesPlain, expert prompt, two worked examples (from a separate set), step by step, and write-code-we-run.
Three sizesGPT-6 Luna, Sol and Astra, all at reasoning effort low, so only the technique changes.
Graded by codeCode answers are run in a sandbox with a 20-second limit; whatever they print is the answer.
# The model writes the program; the sandbox runs it; the output is graded
instructions: "Do not solve the problem yourself. Write one short,
  self-contained Python 3 program that computes the answer and prints only the answer."
model → ```python  …  ```   # about 150–270 tokens instead of 400–700
sandbox → python -I solve.py   (no network, 20 s limit)  →  "512"  →  correct

Evidence

What I haven’t proven yet

Sixteen problems, one run per cell, and problems with exact answers, which flatters the code technique: open-ended writing or judgment can’t simply be computed. With the top model at 16 of 16 everywhere, this set can’t show whether prompt tricks hurt the strongest models, only that they no longer help. Small differences of one or two problems are within run-to-run noise (see How Hard Should It Think?). Projecting today’s size trend onto future models is an argument, not a measurement.

Choices

Size as a time machineThe step from a small to a top model today is a rough preview of the step to the next generation. It is the only forecast you can run.
Fresh problems over benchmarksPublished benchmarks end up in training data. Problems generated today, graded by code, can’t have been memorized.
Cost per right answer as the scoreboardA technique that adds tokens without adding right answers is a tax, and taxes compound across millions of calls.

The longer argument, about what stays scarce when intelligence is abundant, is in the companion essay: When intelligence is abundant.

Sources

  1. Let’s Data Science on Gemini 4 Argon, Oct 2, 2026: 13 of 18 vendor-reported benchmarks, pricing, limited access. ProPakistani: Vals Index 68.9%.
  2. ComputingForGeeks on Claude Opus 5.5, Sep 23, 2026: pricing, Terminal-Bench 4.0 and OSWorld 2.0 scores, effort defaults.
  3. Vellum on Claude Fable 5.1 and Mythos 5.1: Sep 1 release, pricing, benchmarks.
  4. Emergent on “Fable 5.5,” Oct 5, 2026: no announced Fable 5.5; what is confirmed versus rumored.
  5. Pluralsight on GPT-7, Sep 10, 2026: GPT-6 Astra’s Sep 3 release; no confirmed successor; status of leaks.
  6. GPT-6 Astra pricing, Sol and Luna: prices used for cost per right answer.