← DEPT. 02 · CHORUS AI SYSTEMS
EXPERIMENT LIVE CHORUS AI SYSTEMS

Jev vs. the Frontier

RESEARCH NOTE · SEPTEMBER 2026

A small model matched a frontier model on automated decisions, at one-fiftieth of the cost.

91.4% vs 91.0%
$0.10 vs $5.25 PER 1K

HOW IT WORKS

A fair fight: same task, same rules, locked in advance

  • IN / OUT
  • CODE
  • AI MODEL
  • CHECKPOINT
  1. IN Banking77 customer messages, 77 categories
  2. SAME MESSAGES, TWO MODELS
    AI MODEL Jev small, specialized
    AI MODEL Claude Sonnet 5 frontier
  3. CHECKPOINT Confident? pre-registered threshold

    Not confident: routed to a person

  4. CODE Score against a locked test set
  5. OUT 91.4% vs 91.0% $0.10 vs $5.25 per 1,000

Rules written before the run. Whole experiment: $16. Simplified. The full story is on the project site.

The question

Can a small, specialized model do everyday business sorting work as well as a frontier model? If it can, a lot of companies are overpaying for AI.

The test

I set up a realistic triage task on Banking77, a public set of customer banking messages sorted into 77 categories. The rule was the one a real operation would use: answers the model is confident about are accepted automatically, and everything else goes to a person.

To keep the result honest, the rules were written down before the test ran, and the test set was locked so nothing could be tuned against it. The whole experiment cost $16.

The result

On the decisions it made automatically, Jev was right 91.4% of the time. Claude Sonnet 5 was right 91.0% of the time.

Jev did it for $0.10 per thousand messages. Sonnet cost $5.25. Same accuracy, one-fiftieth of the price.

Why it matters

Most AI cost is decided by habit: send everything to the biggest model. Measured carefully, many tasks don’t need it. That’s the routing problem at the heart of the AI Operations Management textbook, shown with real numbers.

What’s next

Phase 2 runs the same test on real emails.