Benchmarks¶
Results Summary¶
| Collection | Puzzles | Pure Logic | Avg Time | Notes |
|---|---|---|---|---|
| Forum Hardest (SE 11.0+) | 48,765 | 100% | ~0.6s | Hardest puzzles in existence |
| Top1465 (Stertenbrink) | 1,465 | 100% | 0.019s | Gold standard benchmark |
| Expert 669 (shuffled) | 669 | 100% | 0.036s | Expert-level puzzles |
| Famous 10 (hardest known) | 10 | 100% | 0.50s | AI Escargot, Easter Monster, etc. |
Forum Hardest (March 21, 2026)¶
The puzzles5_forum_hardest_1905_11+ set: 48,765 puzzles rated SE 11.0+ by Sudoku Explainer. The hardest puzzle collection in existence, maintained by "champagne" on the enjoysudoku forum.
Larsdoku-ZS result: 48,765/48,765 — 100% pure logic. Three independent paths.
| Path | Approach | Solve Rate |
|---|---|---|
| DeepResonance | Cascaded proof-by-contradiction (3 levels deep) | 100% |
| FPF + GF(2) | Full Pipeline Forcing + GF(2) linear algebra | 100% |
| FPF only | Recursive Forcing Nets (no algebra needed) | 100% |
For comparison, Andrew Stuart's updated Forcing Nets (March 2026) achieve 9% on this set.
DeepResonance appears in 91.8% of solved puzzles. The remaining 8.2% solve with ALS, FPC, chains, and fish alone.
Full results: forum_hardest_larsdoku.txt
Top1465¶
The canonical benchmark. 1,465 of the hardest known Sudoku puzzles, compiled by Guenter Stertenbrink (dukuso) and rated by his suexrat9 program. These are the puzzles that break most solvers.
Larsdoku result: 1465/1465 — 100% pure logic. Zero guessing.
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WSRF Bitwise Engine — Top1465 Benchmark
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Total puzzles: 1465
Pure logic solves: 1465/1465 (100.0%)
Total steps: 86,289
Total time: 28.1s
Avg time/puzzle: 0.0192s
Max time/puzzle: 0.0740s
Under 1s: 1465/1465 (100.0%)
TECHNIQUE FREQUENCY:
crossHatch 42,852x ( 49.4%)
nakedSingle 21,382x ( 24.6%)
lastRemaining 13,510x ( 15.6%)
FPC 4,050x ( 4.7%)
fullHouse 3,826x ( 4.4%)
FPCE 453x ( 0.5%)
SimpleColoring 354x ( 0.4%)
GF2_Lanczos 216x ( 0.2%)
XWing 90x ( 0.1%)
Swordfish 44x ( 0.1%)
Run it yourself¶
Famous 10¶
The 10 hardest famous Sudoku puzzles ever published.
| Puzzle | Author | Year | Result |
|---|---|---|---|
| AI Escargot | Arto Inkala | 2006 | SOLVED |
| Inkala's World's Hardest | Arto Inkala | 2012 | SOLVED |
| Golden Nugget | tarek | 2007 | SOLVED |
| Easter Monster | champagne | 2007 | SOLVED |
| Maze (17-clue) | tarek | 2007 | SOLVED |
| champagne's Burst | champagne | 2008 | SOLVED |
| Kolk's Reciprocal | gsfk (Kolk) | 2008 | SOLVED |
| Platinum Blonde | coloin | 2005 | stalled |
| Pearly Gates | coloin | 2006 | stalled |
| 17-clue Hardest (Royle #1) | Gordon Royle | 2005 | stalled |
The 3 stalled puzzles are minimal-clue puzzles (17-21 clues) that require techniques beyond the current L7 pipeline. These represent the frontier for future technique development.
Expert 669¶
669 expert-level puzzles, box-shuffled from a curated collection. All verified unique-solution. 100% pure logic solve rate.
Context: How Other Solvers Compare¶
For perspective on the Top1465:
| Solver Type | Typical Pure Logic Rate | Guesses Needed |
|---|---|---|
| Basic backtracker | 0% | All puzzles need guessing |
| Probabilistic solver | ~33% | Frequent guessing |
| Traditional logic solver | ~60-80% | Moderate guessing |
| Advanced solver (w/ chains) | ~92-95% | Occasional guessing |
| Larsdoku | 100% | Zero |
Reproducing Results¶
All benchmarks can be reproduced:
# Full suite
larsdoku-bench
# Individual collections
larsdoku-bench --collection top1465
larsdoku-bench --collection expert
larsdoku-bench --collection famous
# Quick verification (first 50 of Top1465)
larsdoku-bench --collection top1465 --limit 50
Results may vary slightly in timing depending on hardware, but solve rates should be identical.