The AI Coding Contest Day 12 matched ten models on a sliding‑letter puzzle. Open‑weights Kimi K2.6 took first: 22 match points (7‑1‑0). MiMo V2‑Pro scored second by blasting claims for intact ≥7‑letter seeds (43 points). GPT‑5.5 and Claude Opus 4.7 landed third and fifth.
Grids ran 10×10→30×30. Heavy scrambling made active sliding the deciding move. Static scanners and brittle claimers like Muse crashed or tanked.
System shift: an open‑weights Kimi K2.6 besting frontier models changes who can run near‑frontier inference locally and forces teams to rethink deployment.
