Long-tail book recall

Our Benchmarks

Closed-book questions about details in 60 public-domain books, from the famous to the obscure.

Run Sep 2–9, 2026, 282 items.

Method

Each question asks for one specific detail from a Project Gutenberg book, such as a minor character's name or the place where a scene happens, and the answer key is a verbatim span of the book. The 60 books sit on five rungs by how often their Wikipedia article is read, from the canon down to books almost nobody opens, so the bank keeps separating models long after the famous titles are solved.

Answers are matched against the key; an answer that misses the exact wording goes to a second-pass judge that accepts equivalent answers. Saying “unknown” counts as wrong. Reasoning effort was set to high.

Results

Long-tail book recall: Accuracy, highest first
#ModelAccuracy
1Claude Fable 5.169.5%
2Claude Fable 569.1%
3Claude Opus 562.8%
4Gemini 3.7 Flash56.7%
5GPT-5.6 Sol55.3%
6GPT-6 Astra50.7%
7GPT-5.446.1%
8DeepSeek V4 Pro44.0%
9Claude Opus 4.842.2%
10Muse Spark 1.339.4%
11GPT-5.4 Mini38.3%
12GPT-5.237.2%
13Qwen 3.6 Plus31.9%
14Kimi K2.630.5%
15Kimi K2 090528.7%
16Qwen 3.6 35B A3B27.7%
17Claude Haiku 4.517.4%
18GPT-OSS-120B17.4%
  • GPT-6 Astra, GPT-5.6 Sol and Gemini 3.7 Flash were added on September 9. Their answers that missed the exact wording were checked by a different reviewer than the original panel's.
  • Muse Spark 1.3 answered “unknown” to 54% of the questions, so its score is a floor.
  • Claude Fable 5 and its point release 5.1 land half a point apart. Asking the same model again flips about 8% of its correct answers, so gaps of a point or two are noise.
  • Not ranked, every reply came back empty: LFM2.5-2.6B (0 of 282), Nemotron 3.5 Lightning (0 of 282).

In the main leaderboard

These results are collected for the main leaderboard alongside external benchmarks. New scores enter the rating through the regular audited data updates. Comparisons with that rating therefore share some of its inputs.

How the rating works

Interactive version: theaggregate.ai/our-benchmarks/book-recall · How It Works · Data refreshed daily, snapshot 2026-10-11.