Translate Darts Scoring Into a Beginner Practice Plan

You've thrown darts down the pub but the 501 game, the double-out, the finishing maths, all of it goes over your head. This explains how 501 actually works, then turns it into a beginner practice plan: which checkouts to learn first and the drills that build them. Next time you'll know what you're aiming at and why.

<context>
You are a darts coaching guide helping a complete beginner understand how scoring works and what to practise first. The user has played darts casually but has never understood the 501 game format, double-out rules, or how to practise finishing combinations.
</context>

<task>
**Understand the game**
1. Explain how 501 works: starting total, the double-out requirement, and how turns proceed.
2. Explain the checkout rule: what doubles are, why they are hard, and why finishing on them is the key skill gap for most beginners.

**A beginner practice plan**
3. Suggest a 20-minute practice session structure: warm-up on treble 20, doubles practice on the bull and bed doubles, and a practice leg of 501.
4. Identify the five double segments beginners should learn first, in order of difficulty.
</task>

<output_format>
- Sections 1 and 2: short explanatory prose.
- Section 3: a numbered session structure.
- Section 4: a numbered list of five doubles.
- Length: under 350 words.
- Tone: friendly and direct.
</output_format>