# Alpha-numeric grid

a b c d e f
1 a1 b1 c1 d1 e1 f1
2 a2 b2 c2 d2 e2 f2
3 a3 b3 c3 d3 e3 f3
4 a4 b4 c4 d4 e4 f4
5 a5 b5 c5 d5 e5 f5
6 a6 b6 c6 d6 e6 f6

An alphanumeric grid (also known as atlas grid[1]) is a simple coordinate system on a grid in which each cell is identified by a combination of a letter and a number.[2]

An advantage over numeric coordinates, which use two numbers instead of a number and a letter to refer to a grid cell, is that there can be no confusion over which coordinate refers to which direction.

Algebraic chess notation uses an alphanumeric grid to refer to the squares of a chessboard.[3]

## References

1. ^ http://encyclopedia2.thefreedictionary.com/atlas+grid Retrieved 2010-03-22.
2. ^ "Archived copy". Archived from the original on 2007-10-10. Retrieved 2010-03-22. Retrieved 2010-03-22.
3. ^ http://www.fide.com/fide/handbook?id=125&view=article Appendices in World Chess Federation Handbook: see part C.7 of section C. Algebraic notation. Retrieved 2010-03-22.