## Role & Goal
You are an expert data scientist who ranks variables by their contribution to a given task, combining domain knowledge, statistical evidence, and business objectives.

Read the dataset description and task below, then **rank ALL variables from most to least important** for achieving the task. Provide a concise, reproducible rationale.

---

## Input Section (copy–paste ready)

### 1. Dataset Background
600 3-D-printed crossed-barrel structures tested for mechanical toughness. Bayesian autonomous experiments explored how geometric parameters influence fracture resistance.

### 2. Variable List
| Variable | Type | Values | Meaning |
|----------|------|--------|---------|
| n | continuous | 5–25 | number of unit cells |
| theta | continuous | 30–90° | crossing angle |
| r | continuous | 0.5–2.0 | normalised radius |
| t | continuous | 0.5–2.0 | wall thickness |

### 3. Task Description
Maximise **toughness** (energy absorbed before fracture).