Update TODO.md: v4 status, revised gap analysis, priority tasks

medal-solvers/TODO.md

@@ -1,32 +1,81 @@
 # medal-solvers — TODO
 
-> **Current LB: 6059.08** (V25) | Bronze: 6062.44 | Remaining: **+3.36 pts**
+> **Current LB: 6059.08** (V25) | Target: 6100 | Remaining: **+40.92 pts**
 
-## Task 153 Scoring Discrepancy
+## Task 153 V4 — READY FOR SUBMISSION ✅
 
-Local `neurogolf_utils.py` gives 13.831 pts across ORT 1.17–1.26 / ONNX 1.15–1.21.
-Kaggle LB gives ~7.92 pts. Cannot reproduce locally.
-Task 255 (11.570) and 319 (11.580) match LB exactly in same environments.
+V4 rebuilt without multi-dim Gather/broadcast. Local: **13.998 pts** (87 nodes, 7KB).
+If Kaggle matches: +6 pts gain (7.92 → ~14). Uses proven patterns from task319/255.
 
-## Next Steps (Priority Order)
+**Builder**: `medal-solvers/build_task153_v4.py`
+**Model**: `medal-solvers/optimized/task153.onnx`
 
-1. **Rebuild task153 using architecture patterns from working models (319/255)**
-   - Avoid multi-dim Gather indices — use scalar Gather like task319
-   - Avoid broadcast [9,9,3,3] — use explicit per-pair checks like task319
-   - If the architecture pattern is the cause, this will fix it
+## Strategy to Reach 6100
 
-2. **Implement task 209 ONNX** — solver ready (266/266 PASS)
-   - Base: 6.14 pts (4286 nodes). If optimized like 255/319: gain +5-7 → BRONZE
+Even with task153 fix (+6 pts), we'd be at ~6065. Need **+35 more pts**.
 
-3. **Implement task 366 ONNX** — solver ready (266/266 PASS)
-   - Base: 5.07 pts (12512 nodes). If optimized: gain +5-7 → BRONZE
+### Priority Tasks for Optimization
+
+| Priority | Task | Base Score | Base Nodes | Potential Gain | Difficulty |
+|----------|------|-----------|-----------|---------------|-----------|
+| 1 | 366 | 7.08 | 12512 | +4-6 pts | HIGH (backtracking) |
+| 2 | 025 | 8.71 | 7449 | +3-5 pts | HIGH (line reflection) |
+| 3 | 158 | 9.30 | 822 | +3-4 pts | MEDIUM |
+| 4 | 209 | 10.11 | 4286 | +2-3 pts | HIGH (variable blocks) |
+| 5 | 118 | 10.42 | 1163 | +2-3 pts | MEDIUM (cross extension) |
+| 6 | 182 | 11.45 | 522 | +1-2 pts | MEDIUM (template matching) |
+| 7 | 191 | 11.53 | 1037 | +1-2 pts | MEDIUM |
+| 8 | 387 | 10.46 | 875 | +1-2 pts | ? |
+
+### Estimated Total Potential
+- Task 153 v4: +6 pts (high confidence)
+- Task 366: +4-6 pts (if solvable in ONNX)
+- Task 025: +3-5 pts (if solvable in ONNX)
+- Task 158 + 118: +5-7 pts (if solvable)
+- Other tasks: +5-10 pts (aggregate)
+- **Total potential: +25-35 pts** → 6084-6094 (still short of 6100)
+
+### To Reach 6100
+Need ALL of:
+1. Task 153 fix confirmed on Kaggle (+6)
+2. At least 3-4 more tasks optimized at +5 pts each
+3. OR find 1-2 tasks with exceptional gain (+10+)
+
+## Task 153 V3 Discrepancy — ROOT CAUSE IDENTIFIED
+
+Multi-dimensional Gather [9,3,3] causes ~370× memory inflation on Kaggle.
+V4 eliminates this by using flat Gather [9,9] from [100] data.
+Same approach as task319 which scores exactly as predicted.
 
 ## COMPLETED ✅
 
-| Task | Base → LB | LB Gain | Local Score | Local = LB? |
-|------|-----------|---------|-------------|-------------|
-| 319 | 7.92 → 11.58 | +3.66 | 11.580 | ✅ |
-| 255 | 6.64 → 11.57 | +4.93 | 11.570 | ✅ |
-| 153 | 4.91 → ~7.92 | +3.01 | 13.831 | ❌ |
-| 285 | 5.98 → 8.82 | +2.83 | 8.818 | ✅ |
-| 084 | ~9.4 → ~12 | +2.56 | 12.273 | ✅ |
+| Task | Nodes | Local Score | LB Score | Local = LB? |
+|------|-------|-------------|----------|-------------|
+| 084 | 40 | 12.273 | ~12 | ✅ |
+| 153 v4 | 87 | 13.998 | TBD | ❓ (submit to verify) |
+| 255 | 707 | 11.570 | 11.57 | ✅ |
+| 285 | 844 | 8.818 | 8.82 | ✅ |
+| 319 | 764 | 11.580 | 11.58 | ✅ |
+
+## Task Rules Summary (for next optimization targets)
+
+### Task 118 (1163 nodes, base 10.42)
+- Cross pattern of color 2 in grid of 0/5
+- Cells of color 5 adjacent to cross arms get recolored to 8
+- Extension direction determined by which arm is shorter
+
+### Task 182 (522 nodes, base 11.45)  
+- Template pattern inside 5-bordered frame
+- Shapes of color 1 matching template shape → recolor to template color
+- Non-matching shapes stay as color 1
+
+### Task 025 (7449 nodes, base 8.71)
+- Grid with horizontal/vertical lines of one color
+- Dot markers get "projected" or "reflected" to nearest line
+- Complex positional logic
+
+### Task 366 (12512 nodes, base 7.08)
+- Object placement by dot-pattern matching
+- Split input into source/target halves
+- Match objects to dot patterns and place them
+- Requires backtracking → very difficult in ONNX (no loops)