How to Read Diamonds on a Billiards Table

TL;DR: Each long rail of a billiards table has 7 diamond markers (some tables have 5). Count them 1-7 starting from your end. The diamond numbers are the foundation for all Diamond System calculations.

What are diamonds?

Small inlaid markers on the wooden rail above the cushion. They serve as visual reference points. Standard tournament tables have 7 per long rail.

Numbering system

Standard Korean valuation extends across all rails as a continuous number line:

Your long rail:           1   2   3   4   5   6   7
Far short rail:           8   9  10
Opposite long rail:      11  12  13  14  15  16  17
Near short rail:         18  19  20
Your long rail (back):   21  22  23  24  25  26  27

Beginner pitfalls

1. Counting from corner instead of mid-rail edge — cushion-edge diamond is 0, not 1
2. Forgetting 5-diamond vs 7-diamond table layouts
3. Using diamond as exact aim point — it's reference, not target
4. Mixing 'starting position' diamond with 'first cushion contact' diamond — they are different

Practice exercise

For each ball position on a real or simulated table, identify:

• Which long rail it's nearest to
• Which two diamonds it's between
• How far between them (e.g., diamond 4.3 = between 4 and 5, closer to 4)

30 minutes of this drill makes Diamond System calculations 3× faster.