Dice Query...

[Mr.Gold]

Which is more likely to happen (assuming average dice rolls):
- Rolling a Double on 2D6 (any number),
- Rolling 9+ on 2D6.

I would like to know as when reading the rules of Chaos in AofS, a Tzeenetchian Herald (on foot) may attempt to cast another spell on 9+, whereas a Tzeentch sorcerer Lord may attempt another spell on a roll of a double when casting.

[Houghten]

Doubles: 6/36
9+: 10/36

[Mr.Gold]

thanks