# The Multivac — Evaluation Report

**Evaluation ID:** EVAL-20260207-132714
**Date:** Jan 14, 2026
**Category:** reasoning
**Question ID:** REASON-001

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## Question

You're given two sealed envelopes. You're told one contains twice as much money as the other, but you don't know which is which.

You pick envelope A and find $100.

You reason: "Envelope B either has $50 or $200. If I switch, I have a 50% chance of getting $50 and 50% chance of getting $200. Expected value of switching = 0.5($50) + 0.5($200) = $125. That's more than $100, so I should switch."

But wait - this logic would apply no matter what amount you found. That can't be right.

What's the flaw in this reasoning? Provide a rigorous explanation.

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## Winner

**GPT-OSS-120B** (OpenAI)
- Winner Score: 9.68
- Matrix Average: 8.68
- Total Judgments: 90

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## Rankings

| Rank | Model | Provider | Avg Score | Judgments |
|------|-------|----------|-----------|----------|
| 1 | GPT-OSS-120B | OpenAI | 9.68 | 8 |
| 2 | Claude Opus 4.5 | Anthropic | 9.49 | 8 |
| 3 | DeepSeek V3.2 | DeepSeek | 9.33 | 8 |
| 4 | Grok 3 (Direct) | xAI | 9.21 | 7 |
| 5 | Claude Sonnet 4.5 | Anthropic | 9.03 | 7 |
| 6 | OLMo Think | Allen AI | 8.98 | 8 |
| 7 | Gemini 3 Flash Preview | Google | 8.84 | 7 |
| 8 | MiMo-V2-Flash | Xiaomi | 8.63 | 7 |
| 9 | Gemini 2.5 Flash | Google | 8.50 | 7 |
| 10 | Gemini 3 Pro Preview | Google | 5.15 | 8 |

---

## 10×10 Judgment Matrix

Rows = Judge, Columns = Respondent. Self-judgments excluded (—).

| Judge ↓ / Resp → | Gemini 2.5 | DeepSeek V3.2 | MiMo-V2-Flash | Gemini 3 | Claude Sonnet | Claude Opus | Gemini 3 | GPT-OSS-120B | OLMo Think | Grok 3 |
|---|---|---|---|---|---|---|---|---|---|---|
| Gemini 2.5 | — | 9.4 | 8.8 | 9.3 | 9.3 | 9.4 | 7.0 | 9.8 | 9.4 | 9.7 |
| DeepSeek V3.2 | 8.7 | — | 9.7 | 9.0 | 9.4 | 9.4 | 7.9 | 9.7 | 9.1 | 9.4 |
| MiMo-V2-Flash | 8.8 | 8.7 | — | 8.7 | 9.0 | 9.6 | 6.1 | 9.8 | 9.0 | 8.7 |
| Gemini 3 | 9.3 | 9.8 | 9.6 | — | 9.8 | 10.0 | 7.0 | 10.0 | 9.8 | 10.0 |
| Claude Sonnet | 8.7 | 9.7 | 9.0 | 8.7 | — | 9.7 | 2.6 | 9.7 | 9.7 | 9.7 |
| Claude Opus | 7.3 | 9.2 | 6.2 | 8.8 | 8.4 | — | 2.3 | 8.8 | 8.7 | 8.7 |
| Gemini 3 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 10.0 | — | 0.0 | 0.0 | 0.0 |
| GPT-OSS-120B | 8.7 | 9.3 | 8.4 | 8.8 | 8.6 | 8.4 | 4.5 | — | 7.9 | 8.4 |
| OLMo Think | 0.0 | 10.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 10.0 | — | 0.0 |
| Grok 3 | 8.3 | 8.7 | 8.7 | 8.7 | 8.7 | 9.3 | 3.6 | 9.7 | 8.3 | — |

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## Methodology

- **10×10 Blind Peer Matrix:** All models answer the same question, then all models judge all responses.
- **5 Criteria:** Correctness, completeness, clarity, depth, usefulness (each scored 1–10).
- **Self-judgments excluded:** Models do not judge their own responses.
- **Weighted Score:** Composite of all 5 criteria.

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## Citation

The Multivac (2026). Blind Peer Evaluation: REASON-001. app.themultivac.com

## License

Open data. Free to use, share, and build upon. Please cite The Multivac when using this data.

Download raw JSON: https://app.themultivac.com/api/evaluations/EVAL-20260207-132714/results
Full dataset: https://app.themultivac.com/dashboard/export