# FormulaCascade Benchmark — Evaluation Subset (eval-200, v2)

This is a 200-task stratified evaluation subset of the full FormulaCascade Benchmark (11,171 tasks).

## Sampling Design (v2)

- **200 tasks total**: 50 per tier × 4 tiers
- **Balanced**: 25 single-sheet + 25 cross-sheet per tier
- **Quality-filtered**: all tasks are verdict=RELEASE, total QC score ≥ 26, D3 ≥ 3, D4 ≥ 3
- **Diverse**: maximizes domain and formula-family coverage within each tier
- **Reproducible**: sampled with seed=42 using `resample_eval200_v2.py`

### v2 Improvements over v1
- All 200 tasks are `verdict=RELEASE` (v1 had 31 HOLD tasks in T4_STANDARD)
- Minimum QC score raised to 26/30 (v1 allowed 25)
- T2_HARD: removed extreme outliers with total_masked > 2000
- T4_STANDARD: depth-stratified (depth=2: 70%, depth=3–4: 20%, depth=5+: 10%) for better differentiation from T3_MEDIUM
- T1_FRONTIER depth=2 tasks require total_masked ≥ 50 to ensure genuine difficulty

## Tier Distribution

| Tier | Count | Single | Cross | Depth Range | Avg Depth | QC Score (avg) |
|------|-------|--------|-------|-------------|-----------|----------------|
| T1_FRONTIER | 50 | 25 | 25 | 2–45 | 10.5 | 27.6 |
| T2_HARD | 50 | 25 | 25 | 3–4 | 3.4 | 27.8 |
| T3_MEDIUM | 50 | 25 | 25 | 2 | 2.0 | 27.8 |
| T4_STANDARD | 50 | 25 | 25 | 2–8 | 2.7 | 26.0 |

## Domain & Formula Coverage

| Domain | Count | Formula Family | Count |
|--------|-------|----------------|-------|
| general | 35 | arithmetic | 68 |
| finance | 34 | conditional | 42 |
| sales | 31 | aggregation | 39 |
| data_analysis | 28 | lookup | 33 |
| education | 19 | ranking | 6 |
| operations | 19 | | |
| hr | 17 | | |
| engineering | 17 | | |

## Directory Structure

```
FormulaCascade_Benchmark_eval_200/
├── README.md
├── manifest_eval200.jsonl        # 200-task metadata (v2)
├── fcb_id_mapping.json           # FCB-ID ↔ task_id mapping (200 tasks)
├── eval200_summary_v2.json       # sampling statistics summary
├── T1_FRONTIER/
│   ├── release/FCB-NNNNN/        # task_description.json + task-NNNNN.xlsx
│   └── internal/FCB-NNNNN/       # full provenance + ground truth
├── T2_HARD/
├── T3_MEDIUM/
└── T4_STANDARD/
```

## Usage

For evaluation, use `release/FCB-NNNNN/task_description.json` (prompt) and
`release/FCB-NNNNN/task-NNNNN.xlsx` (masked workbook) as solver input.

Ground truth is in `internal/FCB-NNNNN/ground_truth_target.json` (layer-1 target cells).

See the full benchmark README for evaluation protocol details.

## Tier Counts
- **T1_FRONTIER**: 50 tasks (all RELEASE, depth 2–45, avg depth 10.5)
- **T2_HARD**: 50 tasks (all RELEASE, depth 3–4)
- **T3_MEDIUM**: 50 tasks (all RELEASE, depth 2)
- **T4_STANDARD**: 50 tasks (all RELEASE, depth 2–8)