Quote Originally Posted by Budwise
and that is?
Something like this:

Attacker's Chance to Hit = 1.9% + (Attack - TargetDefense)*20%

Keep in mind that in MTW attack speeds are a lot faster and the CtH is subject to a wide range of modifiers.

Reference:
https://forums.totalwar.org/vb/showp...31&postcount=9

There's a lot of stat discussion in that thread as well.