# Claude 4.1 Opus Thinking vs BERT base / Fine-tuned on case law and contract corpora Chalkidis et al. (2020) (ContractNLI)

> Side-by-side benchmark comparison for Claude 4.1 Opus Thinking and BERT base / Fine-tuned on case law and contract corpora Chalkidis et al. (2020) (ContractNLI) across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-4-1-opus-thinking-vs-native-contractnli-bert-base-fine-tuned-on-case-law-and-contract-corpora-chalkidis-et-al-2020
- Last updated: October 1, 2026

- Shared sourced benchmarks: 0
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

No benchmark verdict yet: there is no shared sourced benchmark row for Claude 4.1 Opus Thinking and BERT base / Fine-tuned on case law and contract corpora Chalkidis et al. (2020) (ContractNLI).

## Summary

- Claude 4.1 Opus Thinking and BERT base / Fine-tuned on case law and contract corpora Chalkidis et al. (2020) (ContractNLI) do not currently share a sourced benchmark row. The mirror therefore compares metadata, pricing, context windows, and each model's separately reported coverage without naming a benchmark winner.

## Model Snapshot

| Property | Claude 4.1 Opus Thinking | BERT base / Fine-tuned on case law and contract corpora Chalkidis et al. (2020) (ContractNLI) |
|----------|----------|----------|
| Creator | Anthropic | Koreeda and Manning |
| Type | Proprietary | Research system |
| Reasoning | Reasoning | Unspecified |
| Context | 200K | null |
| Independent public score (not head-to-head) | 40.46 | null |
| Benchmarks Covered | 0 | 0 |
| Pricing (input/output) | Pricing unavailable / Pricing unavailable | Pricing unavailable / Pricing unavailable |

## Category Breakdown

### Reasoning

- Winner: Insufficient shared evidence
- Claude 4.1 Opus Thinking public-lane score: 74.6 (Unranked · 2 rankable rows)
- BERT base / Fine-tuned on case law and contract corpora Chalkidis et al. (2020) (ContractNLI) public-lane score: Coming soon

### Multimodal & Grounded

- Winner: Insufficient shared evidence
- Claude 4.1 Opus Thinking public-lane score: 61.1 (Unranked · 1 rankable row)
- BERT base / Fine-tuned on case law and contract corpora Chalkidis et al. (2020) (ContractNLI) public-lane score: Coming soon

### Knowledge

- Winner: Insufficient shared evidence
- Claude 4.1 Opus Thinking public-lane score: 42.9 (Estimated · #90/170)
- BERT base / Fine-tuned on case law and contract corpora Chalkidis et al. (2020) (ContractNLI) public-lane score: Coming soon

### Instruction Following

- Winner: Insufficient shared evidence
- Claude 4.1 Opus Thinking public-lane score: 65.1 (#69/124)
- BERT base / Fine-tuned on case law and contract corpora Chalkidis et al. (2020) (ContractNLI) public-lane score: Coming soon

## FAQ

### Can I compare Claude 4.1 Opus Thinking and BERT base / Fine-tuned on case law and contract corpora Chalkidis et al. (2020) (ContractNLI) on BenchLM yet?

Not fully yet. BenchLM is tracking both models, but sourced benchmark coverage is still incomplete for a fair score-level comparison.

### Why does this page show "coming soon" values?

BenchLM only calls winners when public benchmark coverage is available on both sides of the comparison.

## Related Comparisons

- [Claude 4.1 Opus Thinking vs Claude 4.1 Opus](/compare/claude-4-1-opus-vs-claude-4-1-opus-thinking)
- [BERT base / Fine-tuned on case law and contract corpora Chalkidis et al. (2020) (ContractNLI) vs Claude 4.1 Opus](/compare/claude-4-1-opus-vs-native-contractnli-bert-base-fine-tuned-on-case-law-and-contract-corpora-chalkidis-et-al-2020)
- [Claude 4.1 Opus Thinking vs GPT-6 Astra](/compare/claude-4-1-opus-thinking-vs-gpt-6-astra)
- [BERT base / Fine-tuned on case law and contract corpora Chalkidis et al. (2020) (ContractNLI) vs GPT-6 Astra](/compare/gpt-6-astra-vs-native-contractnli-bert-base-fine-tuned-on-case-law-and-contract-corpora-chalkidis-et-al-2020)

## Explore More

- [Claude 4.1 Opus Thinking profile](/models/claude-4-1-opus-thinking)
- [BERT base / Fine-tuned on case law and contract corpora Chalkidis et al. (2020) (ContractNLI) profile](/models/native-contractnli-bert-base-fine-tuned-on-case-law-and-contract-corpora-chalkidis-et-al-2020)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)