ConstraintBench (Joint Optimality) - Production Mix: leaderboard

Metric: Joint optimality rate (%): share of the domain's 20 tasks whose solution is feasible and within 0.1 percent of the solver-proven optimum (production mix domain); ConstraintBench's 200 fully specified constrained-optimization tasks in natural language (20 per operations-research domain, each Gurobi-solved to proven optimality); the model returns a structured solution directly, without a solver, which a deterministic verifier checks against every constraint; one trial per task, OpenAI models at high reasoning effort and Claude with extended thinking (55,000 reasoning tokens), Gemini at its default; higher is better. Source: arxiv.org. Saturation forecast: Around January 2027. 6 models tracked.

Top models

#ModelScoreOverall rank
1Claude Opus 4.6 (Thinking)85#60 (Claude Opus 4.6)
2GPT-5.2 (High)75#105 (GPT-5.2)
3Gemini 3 Pro (Preview)35#64
4O4 Mini (High)30#172 (O4 Mini)
5Claude Opus 4.5 (Thinking)25#79 (Claude Opus 4.5)

No result here: #3 Claude Opus 5.5, #5 GPT-6 Astra, #8 Claude Fable 5.1.

Interactive version: theaggregate.ai/benchmark?slug=constraintbench-joint-optimality-production-mix · How It Works · Data refreshed daily, snapshot 2026-10-11.