Benchmark Almanac

FrontierMath Erdős

GPT-6.1 Sol 4.41% leads since September 2026
Not in model cards

Models try to prove or disprove 68 open Erdős problems in Lean 4. A result counts only if the Lean checker accepts the full proof.

By late October 2026, 17 of the 68 conjectures had been resolved by Epoch's runs or by others.

Made by
Epoch AI
Released
September 2026
Kind
Research mathematics
Level
Research frontier
Scored
Checked automatically
Answers
Written proof
Tasks
All public
Strongest model tested
Gemini 4 Carbon #2 on the capability index
Last model added
October 2026
Scores refreshed
November 12th, 2026

In the authors’ words

We introduce FrontierMath Erdős (FME), a benchmark of 68 Erdős problems that are open as of August 2026. To solve a task in FME, AI systems must resolve (prove or disprove) one of the 68 conjectures in the proof assistant Lean. Our 68 problems were selected by the second author among 652 open problems on erdosproblems.com for their mathematical interest and difficulty. AIs have recently resolved several open problems in mathematics, but these demonstrations fall short of a systematic study of AI capabilities. FME evaluates every AI model on the same fixed problems, autonomously and under the same budget. We evaluated five AIs with a budget of $300 per problem. One (GPT-6 Astra) scored 3%, and all others scored 0%.

Abstract of FrontierMath Erdős (arXiv:2609.25050, CC0)
15
Models scored on its own leaderboard

GPT-6.1 Sol leads with 4.41%

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.

15 models. Scroll sideways for the rest.

  1. 4.41 GPT-6.1 Sol
  2. 2.94 GPT-6 Astra
  3. 2.94 Claude Opus 5.5
  4. 2.94 Gemini 4 Carbon
  5. 2.90 Claude Sonnet 5.5
  6. 1.47 GPT-6 Sol
  7. 1.47 Gemini 4 Argon
  8. 0.0 GPT-5.5
  9. 0.0 Claude Fable 5
  10. 0.0 GPT-5.6 Sol
  11. 0.0 Kimi K3
  12. 0.0 Claude Opus 5
  13. 0.0 Claude Fable 5.1
  14. 0.0 Gemini 3.8 Flash
  15. 0.0 Grok 4.7
  1. 1 GPT-6.1 Sol max 4.41%
  2. 2 GPT-6 Astra max 2.94%
  3. 3 Claude Opus 5.5 max 2.94%
  4. 4 Gemini 4 Carbon high; task version 0.1.11rc11 2.94%
  5. 5 Claude Sonnet 5.5 max 2.90%
  6. 6 GPT-6 Sol max 1.47%
  7. 7 Gemini 4 Argon high 1.47%
  8. 8 GPT-5.5 xhigh 0%
  9. 9 Claude Fable 5 max 0%
  10. 10 GPT-5.6 Sol max 0%
  11. 11 Kimi K3 max 0%
  12. 12 Claude Opus 5 max 0%
  13. 13 Claude Fable 5.1 max 0%
  14. 14 Gemini 3.8 Flash high 0%
  15. 15 Grok 4.7 xhigh 0%

Source: Official FrontierMath Erdős leaderboard

#ModelScoreSettingDateSource
1 GPT-6.1 Sol 4.41% max, Epoch Sep 2026 Official leaderboard
2 GPT-6 Astra 2.94% max, Epoch Sep 2026 Official leaderboard
3 Claude Opus 5.5 2.94% max, Epoch Sep 2026 Official leaderboard
4 Gemini 4 Carbon 2.94% high; task version 0.1.11rc11, Epoch Oct 2026 Official leaderboard
5 Claude Sonnet 5.5 2.90% max, Epoch Sep 2026 Official leaderboard
6 GPT-6 Sol 1.47% max, Epoch Sep 2026 Official leaderboard
7 Gemini 4 Argon 1.47% high, Epoch Sep 2026 Official leaderboard
8 GPT-5.5 0% xhigh, Epoch Apr 2026 Official leaderboard
9 Claude Fable 5 0% max, Epoch Jun 2026 Official leaderboard
10 GPT-5.6 Sol 0% max, Epoch Jul 2026 Official leaderboard
11 Kimi K3 0% max, Epoch Jul 2026 Official leaderboard
12 Claude Opus 5 0% max, Epoch Jul 2026 Official leaderboard
13 Claude Fable 5.1 0% max, Epoch Sep 2026 Official leaderboard
14 Gemini 3.8 Flash 0% high, Epoch Sep 2026 Official leaderboard
15 Grok 4.7 0% xhigh, Epoch Sep 2026 Official leaderboard

Epoch AI has run 15 models. We plot every source in the charts below.

3 models have held number one on the official leaderboard since its release in September 2026

Lab claims count from the day the card came out, independent runs from the model’s release. We draw one row each for the benchmark’s own leaderboard and Epoch AI’s runs.

OpenAI
Own leaderboard 3 leaders
GPT-6.1 Sol 4.41%
Epoch AI runs 3 leaders
GPT-6.1 Sol 4.41%

Sources: Official FrontierMath Erdős leaderboard and Epoch AI runs (CC BY 4.0)

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 Run by Epoch AI Best so far
0% 20% 40% 60% 80% 100% 2026 2027 Near the ceiling (85%) GPT-6.1 Sol GPT-5.5 0% 20% 40% 60% 80% 100% 2026 2027 Near the ceiling (85%) GPT-6.1 Sol

Sources: Official FrontierMath Erdős leaderboard and Epoch AI runs (CC BY 4.0)

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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