---
title: "Quality knee — where paying more stops buying quality — Undominated"
canonical: https://undominated.ai/knee/
description: "First frontier step past 10× the running median $/point: gpt-oss-20b → Gemma 3 4B (as of 2026-10-06)."
---

# Quality knee — where paying more stops buying quality — Undominated

> First frontier step past 10× the running median $/point: gpt-oss-20b → Gemma 3 4B (as of 2026-10-06).

# Quality knee

Where paying more on the frontier stops buying quality at a defensible rate. The rule is in data/knee.toml , not in a chart.

As of 2026-10-06, the first frontier step whose $/Arena Elo point exceeds **10×** the running median of prior steps is gpt-oss-20b → Gemma 3 4B at $0.01/pt (threshold $0.00/pt). Condition: standard-delivery Pareto frontier on Arena human-preference Elo, balanced workload (75% input, 25% output). Elo is a relative benchmark score; this is a marginal-cost rule, not a prediction of task success.

Definition source: docs/PRODUCT-SPEC.md. Left of the knee: commodity quality. Right: premium quality.

| From | To | $/pt | Δ Arena Elo |
| --- | --- | --- | --- |
| [Llama 3.1 8B Instruct](/models/meta-llama__llama-3.1-8b-instruct/) | [gpt-oss-20b](/models/openai__gpt-oss-20b/) [Check](/check/openai__gpt-oss-20b/) | 0.000 | +101.2 |
| [gpt-oss-20b](/models/openai__gpt-oss-20b/) | [Gemma 3 4B](/models/google__gemma-3-4b-it/) [Check](/check/google__gemma-3-4b-it/) | 0.009 | +3.1 |
| [Gemma 3 4B](/models/google__gemma-3-4b-it/) | [gpt-oss-120b](/models/openai__gpt-oss-120b/) [Check](/check/openai__gpt-oss-120b/) | 0.000 | +74.6 |
| [gpt-oss-120b](/models/openai__gpt-oss-120b/) | [DeepSeek V4 Flash 0423](/models/deepseek__deepseek-v4-flash/) [Check](/check/deepseek__deepseek-v4-flash/) | 0.001 | +66.7 |
| [DeepSeek V4 Flash 0423](/models/deepseek__deepseek-v4-flash/) | [Gemma 4 26B A4B](/models/google__gemma-4-26b-a4b-it/) [Check](/check/google__gemma-4-26b-a4b-it/) | 0.008 | +1.8 |
| [Gemma 4 26B A4B](/models/google__gemma-4-26b-a4b-it/) | [MiMo-V2.6-Flash](/models/xiaomi__mimo-v2.6-flash/) [Check](/check/xiaomi__mimo-v2.6-flash/) | 0.002 | +22.5 |
| [MiMo-V2.6-Flash](/models/xiaomi__mimo-v2.6-flash/) | [DeepSeek V4.1 Flash](/models/deepseek__deepseek-v4.1-flash/) [Check](/check/deepseek__deepseek-v4.1-flash/) | 0.001 | +6.1 |
| [DeepSeek V4.1 Flash](/models/deepseek__deepseek-v4.1-flash/) | [GLM 5.3 Flash](/models/z-ai__glm-5.3-flash/) [Check](/check/z-ai__glm-5.3-flash/) | 0.008 | +7.1 |
| [GLM 5.3 Flash](/models/z-ai__glm-5.3-flash/) | [MiMo-V2.6-Pro](/models/xiaomi__mimo-v2.6-pro/) [Check](/check/xiaomi__mimo-v2.6-pro/) | 0.014 | +21.4 |
| [MiMo-V2.6-Pro](/models/xiaomi__mimo-v2.6-pro/) | [Gemini 3.8 Flash](/models/google__gemini-3.8-flash/) [Check](/check/google__gemini-3.8-flash/) | 0.410 | +6 |
| [Gemini 3.8 Flash](/models/google__gemini-3.8-flash/) | [Claude Opus 5.5](/models/anthropic__claude-opus-5.5/) [Check](/check/anthropic__claude-opus-5.5/) | 0.340 | +14.7 |

 Copy evidence Download CSV · 11 rows [Input hashes & method version](/data/publications/manifests/ecef83f767cd4d2c21766f6a5b4dffa36c06351f23657542d473bc1a030c0932.json)

 Read citation text and BibTeX The first frontier step exceeding 10 times the running median cost per Arena Elo point is gpt-oss-20b to Gemma 3 4B: $0.008548/point against a $0.001090/point threshold. Standard-delivery Pareto frontier, LMArena human-preference Elo, balanced workload (75% input, 25% output), base context tier. This marginal-cost rule is not a task-success prediction. As of 2026-10-06. Lens: LMArena Elo (CC BY 4.0). https://undominated.ai/knee/
Method: https://undominated.ai/methodology/
Arena data: https://huggingface.co/datasets/lmarena-ai/leaderboard-dataset (CC BY 4.0). Derived calculations by Undominated.ai.
Publication: sha256:ecef83f767cd4d2c21766f6a5b4dffa36c06351f23657542d473bc1a030c0932; calculation SHA-256: 5ae4d0bee9b70298dd437b05df87c32acb407040b50bf88240677f295f25955d; permitted inputs: https://undominated.ai/data/publications/manifests/ecef83f767cd4d2c21766f6a5b4dffa36c06351f23657542d473bc1a030c0932.json

Copy BibTeX Download citation

 @misc{undominated-knee-2026-10-06,
 author = {{Undominated.ai}},
 title = {knee evidence — Undominated.ai},
 year = {2026},
 url = {https://undominated.ai/knee/},
 note = {as of 2026-10-06; LMArena Elo (CC BY 4.0)},
 annote = {Publication: sha256:ecef83f767cd4d2c21766f6a5b4dffa36c06351f23657542d473bc1a030c0932; calculation SHA-256: 5ae4d0bee9b70298dd437b05df87c32acb407040b50bf88240677f295f25955d; permitted inputs: https://undominated.ai/data/publications/manifests/ecef83f767cd4d2c21766f6a5b4dffa36c06351f23657542d473bc1a030c0932.json}
}

## Continue your investigation

 - [Frontier](/frontier/)
- [Reasoning effort](/effort/)
- [Cheapest at](/cheapest-at/)
- [Methodology](/methodology/)