Run against 4-5 test cases per problem. Pass/fail scoring with edge cases.
AST analysis of cyclomatic complexity, nesting depth, loop count, and line count.
Heuristic scoring of naming, comments, blank lines, and line length distribution.
Pythonic idiom detection: type hints, list comprehensions, enumerate/zip, docstrings.
GPT-OSS 20B
DeepSeek V4
DeepSeek V4 Flash (direct)
OpenRouter GPT-OSS 20B
Qwen 3.5 Plus
Nemotron 3 Ultra 550B
Hy3 (Nexum)
Xiaomi MiMo 2.5 (Nexum)
Devstral Latest (Mistral)
Codestral Latest (Mistral)
Groq Llama 3.3 70B
Gemma 4 12B Coder (local)
Mistral Large
Cerebras GPT-OSS 120B
GPT 5.5 Instant 14K
Two Sum
| Model | ✓ Correctness | ◉ Complexity | ◎ Readability | ✦ Style | Composite |
|---|---|---|---|---|---|
| GPT-OSS 20B 🏆 | 80.0 | 86.5 | 85.0 | 93.0 | |
| DeepSeek V4 | 80.0 | 88.0 | 85.0 | 88.0 | |
| DeepSeek V4 Flash (direct) | 80.0 | 88.5 | 85.0 | 88.0 | |
| OpenRouter GPT-OSS 20B | 80.0 | 86.5 | 85.0 | 93.0 | |
| Qwen 3.5 Plus | 80.0 | 88.0 | 85.0 | 88.0 | |
| Nemotron 3 Ultra 550B | 80.0 | 88.0 | 85.0 | 88.0 | |
| Hy3 (Nexum) | 80.0 | 88.0 | 85.0 | 88.0 | |
| Xiaomi MiMo 2.5 (Nexum) | 80.0 | 88.5 | 85.0 | 88.0 | |
| Devstral Latest (Mistral) | 80.0 | 88.0 | 85.0 | 88.0 | |
| Codestral Latest (Mistral) | 80.0 | 88.0 | 85.0 | 88.0 | |
| Groq Llama 3.3 70B | 80.0 | 88.0 | 85.0 | 88.0 | |
| Gemma 4 12B Coder (local) | 80.0 | 88.5 | 85.0 | 88.0 | |
| Mistral Large | 80.0 | 88.0 | 85.0 | 88.0 | |
| Cerebras GPT-OSS 120B | 80.0 | 86.5 | 85.0 | 93.0 | |
| GPT 5.5 Instant 14K | 0 | 30 | 85.0 | 88.0 |
FizzBuzz
| Model | ✓ Correctness | ◉ Complexity | ◎ Readability | ✦ Style | Composite |
|---|---|---|---|---|---|
| GPT-OSS 20B | 100.0 | 68.5 | 85.0 | 85.0 | |
| DeepSeek V4 | 100.0 | 68.5 | 85.0 | 85.0 | |
| DeepSeek V4 Flash (direct) | 100.0 | 68.5 | 85.0 | 85.0 | |
| OpenRouter GPT-OSS 20B | 100.0 | 68.5 | 85.0 | 85.0 | |
| Qwen 3.5 Plus | 100.0 | 68.5 | 85.0 | 85.0 | |
| Nemotron 3 Ultra 550B | 100.0 | 68.5 | 85.0 | 85.0 | |
| Hy3 (Nexum) | 100.0 | 68.5 | 85.0 | 85.0 | |
| Xiaomi MiMo 2.5 (Nexum) | 100.0 | 68.5 | 85.0 | 85.0 | |
| Devstral Latest (Mistral) | 100.0 | 68.5 | 85.0 | 85.0 | |
| Codestral Latest (Mistral) | 100.0 | 68.5 | 85.0 | 85.0 | |
| Groq Llama 3.3 70B 🏆 | 100.0 | 100 | 80.0 | 88.0 | |
| Gemma 4 12B Coder (local) | 100.0 | 68.5 | 85.0 | 85.0 | |
| Mistral Large | 100.0 | 68.5 | 85.0 | 85.0 | |
| Cerebras GPT-OSS 120B | 100.0 | 68.5 | 85.0 | 85.0 | |
| GPT 5.5 Instant 14K | 0 | 30 | 85.0 | 85.0 |
Merge Intervals
| Model | ✓ Correctness | ◉ Complexity | ◎ Readability | ✦ Style | Composite |
|---|---|---|---|---|---|
| GPT-OSS 20B 🏆 | 100.0 | 82.7 | 89.3 | 85.0 | |
| DeepSeek V4 | 100.0 | 83.5 | 85.0 | 85.0 | |
| DeepSeek V4 Flash (direct) | 100.0 | 83.5 | 85.0 | 85.0 | |
| OpenRouter GPT-OSS 20B | 100.0 | 83.0 | 87.3 | 85.0 | |
| Qwen 3.5 Plus | 100.0 | 83.8 | 85.0 | 85.0 | |
| Nemotron 3 Ultra 550B | 100.0 | 83.5 | 85.0 | 85.0 | |
| Hy3 (Nexum) | 100.0 | 83.8 | 85.0 | 85.0 | |
| Xiaomi MiMo 2.5 (Nexum) | 100.0 | 82.2 | 89.0 | 85.0 | |
| Devstral Latest (Mistral) | 100.0 | 82.2 | 89.0 | 85.0 | |
| Codestral Latest (Mistral) | 100.0 | 82.2 | 89.0 | 85.0 | |
| Groq Llama 3.3 70B | 100.0 | 82.2 | 89.0 | 85.0 | |
| Gemma 4 12B Coder (local) | 100.0 | 81.8 | 90.0 | 85.0 | |
| Mistral Large | 100.0 | 82.2 | 89.0 | 85.0 | |
| Cerebras GPT-OSS 120B | 100.0 | 83.0 | 87.3 | 85.0 | |
| GPT 5.5 Instant 14K | 0 | 30 | 89.0 | 85.0 |
LRU Cache
| Model | ✓ Correctness | ◉ Complexity | ◎ Readability | ✦ Style | Composite |
|---|---|---|---|---|---|
| GPT-OSS 20B | 100.0 | 81.0 | 88.0 | 90.0 | |
| DeepSeek V4 | 100.0 | 81.4 | 88.2 | 90.0 | |
| DeepSeek V4 Flash (direct) 🏆 | 100.0 | 79.0 | 92.2 | 90.0 | |
| OpenRouter GPT-OSS 20B | 100.0 | 81.0 | 88.0 | 90.0 | |
| Qwen 3.5 Plus | 100.0 | 66.2 | 87.8 | 90.0 | |
| Nemotron 3 Ultra 550B | 100.0 | 68.6 | 87.0 | 90.0 | |
| Hy3 (Nexum) | 100.0 | 76.6 | 87.2 | 90.0 | |
| Xiaomi MiMo 2.5 (Nexum) | 100.0 | 69.0 | 87.0 | 90.0 | |
| Devstral Latest (Mistral) | 100.0 | 80.6 | 86.9 | 90.0 | |
| Codestral Latest (Mistral) | 100.0 | 75.8 | 87.5 | 90.0 | |
| Groq Llama 3.3 70B | 100.0 | 79.8 | 86.7 | 90.0 | |
| Gemma 4 12B Coder (local) | 100.0 | 81.0 | 88.0 | 85.0 | |
| Mistral Large | 100.0 | 69.0 | 87.0 | 90.0 | |
| Cerebras GPT-OSS 120B | 100.0 | 50.4 | 86.7 | 90.0 | |
| GPT 5.5 Instant 14K | 0 | 30 | 87.8 | 85.0 |
JSON Parser
| Model | ✓ Correctness | ◉ Complexity | ◎ Readability | ✦ Style | Composite |
|---|---|---|---|---|---|
| GPT-OSS 20B | 100.0 | 0 | 80.0 | 85.0 | |
| DeepSeek V4 | 100.0 | 0 | 82.0 | 85.0 | |
| DeepSeek V4 Flash (direct) | 100.0 | 0 | 72.0 | 90.0 | |
| OpenRouter GPT-OSS 20B | 100.0 | 0 | 75.1 | 85.0 | |
| Qwen 3.5 Plus 🏆 | 100.0 | 0 | 85.5 | 85.0 | |
| Nemotron 3 Ultra 550B | 100.0 | 0 | 82.0 | 85.0 | |
| Hy3 (Nexum) | 100.0 | 6.2 | 56.2 | 85.0 | |
| Xiaomi MiMo 2.5 (Nexum) | 60.0 | 0 | 82.0 | 85.0 | |
| Devstral Latest (Mistral) | 80.0 | 2.5 | 28.0 | 85.0 | |
| Codestral Latest (Mistral) | 40.0 | 0 | 86.2 | 85.0 | |
| Groq Llama 3.3 70B | 20.0 | 12.4 | 67.0 | 88.0 | |
| Gemma 4 12B Coder (local) | 0.0 | 6.0 | 77.2 | 85.0 | |
| Mistral Large | 0 | 0 | 85.0 | 85.0 | |
| Cerebras GPT-OSS 120B | 0 | 0 | 66.0 | 85.0 | |
| GPT 5.5 Instant 14K | 0 | 30 | 83.2 | 85.0 |
All models handle easy problems
Two Sum and FizzBuzz are essentially solved — all models score 80+ on correctness. The differentiation happens on harder tasks.
JSON parser is the big differentiator
Writing a JSON parser from scratch pushes models to demonstrate real coding ability — this is where the gap widens significantly.
DeepSeek V4 shines on LRU Cache
Uses OrderedDict.move_to_end() for elegant O(1) implementation — scores highest on this problem.
Complexity scores tank on long solutions
JSON parsers are inherently long (50-200 lines), which drags complexity scores. This is expected — we're measuring conciseness, not quality.