John Yang (@jyangballin) outlines a move from 2025 SWE-bench single-task…

Brief

John Yang (@jyangballin) outlines a move from 2025 SWE-bench single-task training—where they claim substantial progress—to a 2026 plan to train on CodeClash for long-horizon, open-ended, competitive head-to-head coding tasks. As a first step they published CC:Train, CodeClash’s official training split with 9 new arenas (2026-01-07).

title: @Arboian: 2025: Train on SWE-bench (single tasks)
2026: Train on CodeClash (long horizon, open ended objective...
author: @Arboian
contenttype: tweet
publication: Twitter/X
published: 2026-01-07T18:37:34+00:00
sourceurl: https://x.com/Ar_boian/status/2008971289348997214

word_count: 67

2025: Train on SWE-bench (single tasks)
2026: Train on CodeClash (long horizon, open ended objectives)

Please check out our work!

John Yang (@jyangballin)

We made great headway at training on SWE-bench style tasks in 2025.

In 2026, what if we expanded code post-training to long-horizon, competitive, head-to-head coding tasks?

As an initial step, we've released CC:Train - CodeClash's official training split of 9 new arenas.

— https://nitter.net/jyangballin/status/2008969656888119462#m