thinking-model-router

What this skill does

# Model Router

## Overview

This is the **master routing skill** for all mental models. Instead of knowing 38 frameworks, start here. Identify your domain and problem type, and this skill points you to the right model(s). Think of it as the "which tool do I use?" guide.

**Core Principle:** Don't memorize models—memorize how to find the right one. Domain + Problem Type → Model.

## Short-Circuit: Skip the Router

**If you already know the right model, invoke it directly — don't route.** This skill is for when you're *unsure* which model fits. If the problem obviously calls for a specific model (e.g., "where's the bottleneck?" → theory-of-constraints; "how would an attacker break this?" → red-team), go straight to it. Routing is overhead you only pay when the match isn't obvious. Likewise, if no model clearly helps, just reason directly — don't force one.

## Quick Router

### Step 1: What's Your Domain?

| Domain | You're working on... |
|--------|---------------------|
| **Coding/Debugging** | Bugs, errors, performance issues, root cause |
| **Architecture** | System design, technical decisions, scalability |
| **Product** | Features, user needs, prioritization, roadmap |
| **Business Strategy** | Competition, growth, market, organization |
| **Personal Decisions** | Career, life choices, major commitments |
| **Abstract/Analytical** | Arguments, ideas, theories, pure reasoning |
| **Risk/Safety** | What could go wrong, preparation, resilience |
| **Innovation** | New ideas, breakthroughs, creative solutions |

### Step 2: What's Your Problem Type?

| Type | You need to... |
|------|----------------|
| **Diagnose** | Find root cause, understand why |
| **Decide** | Choose between options |
| **Understand** | Grasp how something works |
| **Create** | Generate new solutions |
| **Evaluate** | Judge quality or validity |
| **Predict** | Forecast outcomes |
| **Optimize** | Improve performance |

---

## Domain → Model Maps

### 🖥️ Coding & Debugging

```
PROBLEM                          → MODEL(S)
─────────────────────────────────────────────────────
Bug with unknown cause           → Scientific Method, 5 Whys Plus
Performance degradation          → Theory of Constraints, Systems Thinking
Spans multiple services          → Systems Thinking, Feedback Loops
Incident postmortem              → 5 Whys Plus, Systems Thinking
Flaky/intermittent behavior      → Scientific Method (hypothesis testing)
"It works on my machine"         → Map-Territory (model vs reality gap)
```

**Default for debugging:** Start with **5 Whys Plus**, escalate to **Systems Thinking** if it spans components.

---

### 🏗️ Architecture & Technical Decisions

```
PROBLEM                          → MODEL(S)
─────────────────────────────────────────────────────
Technology choice                → Lindy Effect, Reversibility
Build vs buy                     → Opportunity Cost, First Principles
Scalability design               → Systems Thinking, Leverage Points
Microservices vs monolith        → Cynefin, Reversibility
Database selection               → Lindy Effect, Theory of Constraints
API design tradeoffs             → TRIZ (resolve contradictions)
Should we rewrite?               → Second-Order, Opportunity Cost
```

**Default for architecture:** Start with **Reversibility** (is this Type 1 or Type 2?), then **Systems Thinking** for interconnections.

---

### 📦 Product & Feature Development

```
PROBLEM                          → MODEL(S)
─────────────────────────────────────────────────────
What should we build?            → Jobs to be Done
Feature prioritization           → Opportunity Cost, Theory of Constraints
Why aren't users engaging?       → Jobs to be Done, 5 Whys Plus
New product exploration          → Effectuation, First Principles
Should we pivot?                 → Regret Minimization, Reversibility
Product-market fit               → Jobs to be Done, Bayesian
Roadmap planning                 → Theory of Constraints, Opportunity Cost
A/B test interpretation          → Bayesian, Probabilistic
```

**Default for product:** Start with **Jobs to be Done** (what job is the user hiring this for?).

---

### 📈 Business Strategy

```
PROBLEM                          → MODEL(S)
─────────────────────────────────────────────────────
Competitive analysis             → Red Team, Second-Order
Market entry                     → Cynefin, Effectuation
Growth strategy                  → Feedback Loops, Leverage Points
Organizational dysfunction       → Archetypes, Systems Thinking
Resource allocation              → Theory of Constraints, Opportunity Cost
Startup strategy                 → Effectuation, Margin of Safety
M&A evaluation                   → Pre-mortem, Steel-manning
Pricing decisions                → First Principles, Fermi Estimation
```

**Default for strategy:** Start with **Cynefin** (what domain is this problem in?), then match approach.

---

### 🧑 Personal & Career Decisions

```
PROBLEM                          → MODEL(S)
─────────────────────────────────────────────────────
Should I take this job?          → Regret Minimization, Reversibility
Career direction                 → Circle of Competence, Regret Minimization
Major life decision              → Regret Minimization, Pre-mortem
Learning what to learn           → Circle of Competence, Lindy Effect
Negotiation prep                 → Steel-manning, Red Team
Should I start a company?        → Effectuation, Margin of Safety, Pre-mortem
Time allocation                  → Opportunity Cost, Theory of Constraints
```

**Default for personal:** Start with **Regret Minimization** (what will 80-year-old you think?).

---

### 🧠 Abstract & Analytical Thinking

```
PROBLEM                          → MODEL(S)
─────────────────────────────────────────────────────
Evaluating an argument           → Steel-manning, Bayesian
Challenging assumptions          → First Principles, Socratic
Estimating unknowns              → Fermi Estimation, Probabilistic
Updating beliefs                 → Bayesian, Probabilistic
Exploring edge cases             → Thought Experiment, Inversion
Finding logical flaws            → Inversion, Steel-manning
Complex causation                → Systems Thinking, Feedback Loops
Philosophical questions          → Thought Experiment, First Principles
```

**Default for abstract:** Start with **Steel-manning** (argue the strongest opposing view first).

---

### ⚠️ Risk & Safety

```
PROBLEM                          → MODEL(S)
─────────────────────────────────────────────────────
What could go wrong?             → Pre-mortem, Red Team
Security review                  → Red Team, Inversion
Disaster preparation             → Pre-mortem, Margin of Safety
Avoiding catastrophic failure    → Margin of Safety, Via Negativa
Stress-testing plans             → Red Team, Pre-mortem
Probability of failure           → Probabilistic, Bayesian
Building resilience              → Via Negativa, Margin of Safety
```

**Default for risk:** Start with **Pre-mortem** (assume failure, explain why).

---

### 💡 Innovation & Creativity

```
PROBLEM                          → MODEL(S)
─────────────────────────────────────────────────────
Breakthrough needed              → First Principles, TRIZ
Stuck on contradictions          → TRIZ
Limited resources                → Effectuation, Via Negativa
Simplification                   → Via Negativa, Occam's Razor
Challenging "impossible"         → First Principles, TRIZ
New market creation              → Effectuation, Jobs to be Done
Removing complexity              → Via Negativa, Occam's Razor
```

**Default for innovation:** Start with **First Principles** (strip to fundamentals, rebuild).

---

## Quick Reference Card

```
┌─────────────────────────────────────────────────────────────────┐
│                    MENTAL MODEL QUICK ROUTER                     │
├─────────────────────────────────────────────────────────────────┤
│