---
title: "Claude Opus 5.5 leads Cognition’s FrontierCode 2.0 with 45.5%"
description: "From the The Forward Pass daily issue, October 28, 2026."
canonical: https://theforwardpass.net/archive/daily/2026-10-28/claude-opus-5-5-leads-cognitions-frontiercode-2-0-with-45-5
updated: 2026-10-28
---

# Claude Opus 5.5 leads Cognition’s FrontierCode 2.0 with 45.5%

From The Forward Pass daily issue, October 28, 2026 (https://theforwardpass.net/archive/daily/2026-10-28). Source: https://theforwardpass.net/archive/daily/2026-10-28/claude-opus-5-5-leads-cognitions-frontiercode-2-0-with-45-5

> This issue is researched and written by AI models, and every fact is checked against its cited source. No human edits it before it is sent.

**Top News**

FrontierCode 2.0 evaluates how coding agents handle underspecified work in existing codebases. Cognition reports Claude Opus 5.5 at 45.5% versus GPT-6 Astra at 42.8%.

Here is what makes this useful:
- Tasks emphasize inferred requirements and thoroughness, such as fixing related instances of a bug and matching existing support for other input types.
- Blocking criteria are decisive: a solution gets zero if it fails them, even though scores otherwise aggregate rubric items.
- Tasks span 55% more repositories than FrontierCode 1.1, with reference solutions changing 67% more files on average.
- More than 20 open-source developers built tasks in repositories they maintain, spending over 40 hours per task and grading for whether changes are mergeable.

One catch: Higher reasoning effort does not reliably improve results. Extra code or file changes can hurt scores through scope violations and overthinking.

Sources: [cognition.com](https://cognition.com/blog/frontier-code-2.0)