# On what basis have I split the alphabet into 4 sets?

I have split the 26 letters of the alphabet into 4 sets. Here they are:

Set 1: $F G J L N P Q R S Z$
Set 2: $A M T U V W Y$
Set 3: $B C D E K$
Set 4: $H I O X$

Can you determine on what basis have I split them?

• N, S, Z could form a set of their own. – Florian F Jan 27 '15 at 11:16
• @FlorianF I was actually thinking the same, which caused me to hesitate about my answer, until I noticed what I was missing with those. But yeah, they should have had their own. – Kevin Voorn Jan 27 '15 at 11:17

• @Taemyr I know - but they are not symmetrical by drawing a line either horizontally or vertically: Therefore I said that the first group has no real symmetry. – Kevin Voorn Jan 29 '15 at 14:42