How to REALLY choose your main
>Take your full name
>Bob Big Balls
>Assign numbers for each letter in each part of your name (a=1, b=2, c=3 .....) and create averages of those numbers.
>Bob big balls
>(2+15+2)/3, (2+9+7)/3, (2+1+12+12+19)/5
>create a final average with the first three averages you have.
>(((2+15+2)/3)+ ((2+9+7)/3)+ ((2+1+12+12+19)/5))/3 = 7.177777778
>Do the same for all factions in-game (already done for the sake of brevity below). Your new main is the one who's number is CLOSEST to your own.

Beastmen
9.875
Bretonnia
10.88888889
Chaos Dwarfs
9.791666667
Deamons of Chaos
9.947619048
Dark Elves
10.55
Dwarfs
11.83333333
Grand Cathay
9.233333333
Greenskins
12.1
High Elves
10.3
Khorne
11.83333333
Kislev
13
Lizardmen
11.33333333
Norsca
11.66666667
Nurgle
12.83333333
Ogre Kingdoms
11.375
Skaven
12
Slaanesh
9.875
The Empire
11
Tomb Kings
12.25
Tzeentch
12.625
Vampire Coast
11.8
Vampire Counts
13.66666667
Warriors of Chaos
11.60833333
Wood Elves
13.425

I call it the Alphabetical-numeric code or ANC. All words in the english alphabet can be expressed as single numbers.