Reasoning Models Explained: o1, DeepSeek R1, and the New AI Frontier
February 19, 2026 • By TopClanker Team
2026 is the year of reasoning models. But what actually makes o1 or DeepSeek R1 different from GPT-4 or Claude? And more importantly — do you need one?
What's a Reasoning Model?
Traditional LLMs are autoregressive: they predict the next word, one token at a time. Fast, but shallow.
Reasoning models take a different approach. Before answering, they:
- Break down the problem into steps
- Explore multiple solution paths
- Self-correct when they hit dead ends
- Show their work (chain-of-thought)
Think of it as the difference between a calculator (instant answer, no working shown) and a student showing their work on a math test (slower, but you can trace the logic).
The Major Players
🟢 OpenAI o1 / o1-preview
The original reasoning model. Excellent at math, coding, and complex reasoning. Trades speed for accuracy — it thinks longer, gets it right more often.
🔵 DeepSeek R1
Open-source reasoning model that matches or beats o1 on many benchmarks. Released with full weights — anyone can run it locally.
🟣 Anthropic (Claude with Extended Thinking)
Claude doesn't call itself a "reasoning model," but recent updates added extended thinking capabilities. Strong on research and analysis.
The Benchmark Numbers
| Model | MMLU | MATH | GPQA |
|---|---|---|---|
| o1-preview | 92.8% | 85.0% | 78.4% |
| DeepSeek R1 | 90.5% | 87.6% | 71.3% |
| GPT-4 Turbo | 88.7% | 73.0% | 65.0% |
When to Use Reasoning Models
✅ Do use reasoning models for:
- Complex math problems (especially multi-step)
- Debugging and code explanation
- Scientific analysis
- Planning and strategy
- When correctness matters more than speed
❌ Don't use reasoning models for:
- Simple Q&A or chatbots (wasteful)
- High-volume, low-stakes tasks
- Real-time applications needing instant response
- Bulk text generation
The Bottom Line
Reasoning models aren't better than standard LLMs — they're different tools. Use a Ferrari for the race, a truck for the haul. Don't use o1 to write emails.
For most applications, a solid model like GPT-4 Turbo or Claude 3.5 Sonnet is sufficient. Reserve reasoning models for when you genuinely need the extra brainpower.
Coming soon: A full breakdown of running DeepSeek R1 locally. Stay tuned.