# VulcanBench v3 → FrontierCode 1.1 Extended

Calibration · https://benchgap.net/calibration/1665 · data retrieved 2026-10-29

FrontierCode 1.1 Extended is estimated from VulcanBench v3 with a offset logistic curve fitted on 5 models measured on both: y = 0.5454 + (0.6584 − 0.5454) / (1 + exp(−200.00·(x − 0.8698))), R² = 0.40, cross-validated error 3.4 pp. It is used for 1 estimate.

| Estimated model | VulcanBench v3 | FrontierCode 1.1 Extended | Source |
|---|---|---|---|
| [Muse Spark 1.2](https://benchgap.net/model/muse-spark-1-2.md) | 87.0% | 60.3% | estimated ± 3.4 pp, low confidence |

## Fitted on

| Model | VulcanBench v3 | FrontierCode 1.1 Extended |
|---|---|---|
| [Claude Opus 5](https://benchgap.net/model/claude-opus-5.md) | 87.0% | 63.6% |
| [GPT-5.6 Luna](https://benchgap.net/model/gpt-5-6-luna.md) | 85.5% | 55.1% |
| [GPT-5.6 Sol](https://benchgap.net/model/gpt-5-6-sol.md) | 87.0% | 60.6% |
| [GPT-5.6 Terra](https://benchgap.net/model/gpt-5-6-terra.md) | 87.0% | 55.8% |
| [Grok 4.6](https://benchgap.net/model/grok-4-6.md) | 87.0% | 61.3% |