Benchmark Almanac

TasteVal

Claude Opus 5.5 230.4× leads since October 2026
Not in model cards

8 AI R&D tasks. Models iteratively design experiments. Taste measured as the compute needed to reach expert-level scores.

Tasks kept private.

Made by
P-Zero Research
Released
October 2026
Kind
AI research tasks
Level
Research frontier
Scored
Checked automatically
Answers
Agent task
Tasks
Kept private
Strongest model tested
GPT-6 Astra #3 on the capability index
Last model added
September 2026
Scores refreshed
November 12th, 2026

In the authors’ words

We introduce TasteVal, a benchmark to evaluate the experimental research taste of frontier models. We define research taste as the ability to pick interesting problems to solve, design experiments, and interpret experimental results. TasteVal measures the experimental component of research taste; given a fixed research problem, we measure how well a model iteratively designs experiments and draws conclusions from their outcomes. We operationalize experimental research taste as compute efficiency; a Researcher who reaches the same score as an expert human using half the serial experimental compute has twice the experimental taste. Experimental taste thus acts as a multiplier on experimental compute, making it a key input to forecasts of AI progress. TasteVal consists of 8 novel, challenging, open-ended tasks representative of frontier AI R&D. To isolate taste from coding ability, the model under evaluation acts as a Researcher that iteratively designs experiments while a fixed Coder agent implements them and reports their results. The Researcher executes until either the 40 H100 hour or 120 wall-clock hour budgets are exhausted. We recruit 24 human experts, at least 2 per task, and take the best expert attempt per task as the expert baseline. We evaluate 20 models released between 2023 and 2026. The best-performing model, Opus 5.5, exceeds our expert baseline, with a compute multiplier of 2.3x (95% CI 1.15-4.37), at roughly 1/30 of our baseliners' average per-run cost. On TasteVal, the compute multiplier of frontier models has doubled approximately every 3.0 months since December 2025 (95% CI 1.7-5.0), up from every 14 months between 2023 and December 2025. Measured by final normalized performance, frontier models show no trend break, doubling every 14.6 months. To keep TasteVal uncontaminated, we do not release the tasks.

Abstract of TasteVal: Measuring the Experimental Research Taste of AI Systems Against Human Experts (arXiv:2610.06824, CC0)
20
Models scored on its own leaderboard

Claude Opus 5.5 leads with 230.4× among models released by September 2026

Best score per model from the benchmark's own leaderboard, read on November 12th, 2026. Where a model ran with several settings or harnesses, we keep its best.

The newest model with a score here came out in September 2026, and nobody has tested a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:

  1. 1 Claude Opus 5.5 max 230.4×
  2. 2 Claude Fable 5.1 max 171.6×
  3. 3 GPT-6 Astra max 160.2×
  4. 4 Claude Opus 5 max 128.6×
  5. 5 Claude Opus 4.8 max 84.2×
  6. 6 GLM-5.3 max 59.2×
  7. 7 GPT-5.6 Sol max 59.0×
  8. 8 Claude Opus 4.7 max 50.1×
  9. 9 GPT-5.5 xhigh 47.0×
  10. 10 Kimi K3 reasoning on 45.3×
  11. 11 Claude Opus 4.6 max 40.4×
  12. 12 GPT-5.2 high 27.7×
  13. 13 GPT-5.4 xhigh 21.3×
  14. 14 Claude Opus 4.5 24k thinking budget 11.8×
  15. 15 GPT-5 high 11.6×
  16. 16 Kimi K2.5 max effort, 96k output 8.60×
  17. 17 o3 high 8.28×
  18. 18 o1 high 6.71×
  19. 19 GPT-4o May 2024 5.96×
  20. 20 GPT-4 Jun 2023 2.72×

Source: Official TasteVal leaderboard

#ModelScoreSettingDateSource
1 Claude Opus 5.5 230.4× max Sep 2026 Official leaderboard
2 Claude Fable 5.1 171.6× max Sep 2026 Official leaderboard
3 GPT-6 Astra 160.2× max Sep 2026 Official leaderboard
4 Claude Opus 5 128.6× max Jul 2026 Official leaderboard
5 Claude Opus 4.8 84.2× max May 2026 Official leaderboard
6 GLM-5.3 59.2× max Aug 2026 Official leaderboard
7 GPT-5.6 Sol 59.0× max Jul 2026 Official leaderboard
8 Claude Opus 4.7 50.1× max Apr 2026 Official leaderboard
9 GPT-5.5 47.0× xhigh Apr 2026 Official leaderboard
10 Kimi K3 45.3× reasoning on Jul 2026 Official leaderboard
11 Claude Opus 4.6 40.4× max Feb 2026 Official leaderboard
12 GPT-5.2 27.7× high Dec 2025 Official leaderboard
13 GPT-5.4 21.3× xhigh Mar 2026 Official leaderboard
14 Claude Opus 4.5 11.8× 24k thinking budget Nov 2025 Official leaderboard
15 GPT-5 11.6× high Aug 2025 Official leaderboard
16 Kimi K2.5 8.60× max effort, 96k output Jan 2026 Official leaderboard
17 o3 8.28× high Apr 2025 Official leaderboard
18 o1 6.71× high Dec 2024 Official leaderboard
19 GPT-4o May 2024 5.96× May 2024 Official leaderboard
20 GPT-4 Jun 2023 2.72× Jun 2023 Official leaderboard

Number one over time

Lab claims count from the day the card came out, independent runs from the model’s release.

Anthropic
Own leaderboard 1 leader
Claude Opus 5.5 230.4×

Source: Official TasteVal leaderboard

Scores over time

All the scores we have, one dot each, so a model tested at several settings appears more than once.

On the benchmark’s own leaderboard
0.00× 50.0× 100.0× 150.0× 200.0× 250.0× 2023 2024 2025 2026 0.00× 50.0× 100.0× 150.0× 200.0× 250.0× 2023 2024 2025 2026

Source: Official TasteVal leaderboard

No lab model card reports it yet

We read the headline results of 522 launch posts from 52 labs, and none of them list this benchmark.

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