Head to head
Kev 4B scores 76.8 and Span-02 79.5 on the System One Index. Kev 4B is more accurate on 6 of 16 text datasets, Span-02 on 10. Same cases, same request, same scorer.
| Kev 4B | Span-02 | |
|---|---|---|
| System One Index | 76.8 | 79.5 |
| English | 78.3 | 77.9 |
| Arabic | 74.8 | 82.3 |
| Vision Index | – | 86.1 |
| Calibration error | 5.1% | 10.5% |
| Median latency | 552 ms | 204 ms |
| Cost per 1,000 calls | $0.010 | $0.005 |
| Kev 4B | Span-02 | |
|---|---|---|
| AG News English | 90.5 | 86.5 |
| SST-2 English | 92.5 | 95.5 |
| SST-5 English | 52.0 | 57.5 |
| DAIR Emotion English | 54.5 | 56.0 |
| Banking77 English | 88.0 | 82.0 |
| BoolQ English | 91.5 | 90.0 |
| XNLI English English | 90.7 | 83.3 |
| Typed decisions English | 66.3 | 72.1 |
| XNLI French French | 79.3 | 73.3 |
| XNLI Arabic Arabic | 72.7 | 66.0 |
| MASSIVE scenario Arabic | 57.0 | 71.0 |
| MASSIVE intent Arabic | 76.5 | 86.0 |
| OSACT4 offensive Arabic | 88.5 | 97.0 |
| Tweet sentiment Arabic | 63.0 | 76.0 |
| MIRACL rerank Arabic | 79.5 | 88.5 |
| MIRACL pairwise Arabic | 86.5 | 91.5 |
| Kev 4B | Span-02 | |
|---|---|---|
| SST-2, as an image | – | 92.5 |
| Arabic sentiment, as an image | – | 70.0 |
| Oxford-IIIT Pet | – | 92.5 |
| VQAv2 yes/no | – | 87.0 |
| CountBench | – | 88.5 |
Model pages: Kev 4B · Span-02. Latency for API models is the median per call through OpenRouter, timed from a cloud server with 8 calls in flight.