Big news: DeepSeek-V4.1-Flash-20261017 (Max) by @deepseek_ai is now the #1 open model in Agent Arena! It just landed at #11 overall with +5.1% net improvement across +7.5K real-world sessions.
This performance also reshapes the Agent Arena Pareto frontier! All models above V4.1-Flash 20261017 in performance are proprietary at much higher cost. At $0.20 median cost per task, that’s ~37% of GPT-6.1 Sol’s improvement for about 27% of the cost.
By signal, this release achieves:
- #8 in Confirmed Success with +11.5% (#1 open)
- #11 in Praise vs. Complaint with +5.9% (#1 open)
- #12 in Bash Reliability with +5.4% (#1 open)
- #13 in Steerability with +2.5% (#1 open)
- No issues with Tool Hallucination
Find more info on signals at the link in thread on Agent Arena.
Congrats to the @deepseek_ai team on this release!


