These factors have been based on looking at about 25-30 historical examples of cavalry breaking infantry squares and trying to determine the circumstances that caused each infantry square to be broken.
The common factors were that; the cavalry were of higher unit class, the cavalry were either heavy cavalry or lancers, and wet weather conditions prevented the infantry from firng and allowed the cavalry to close with them.
In more detail though, in 29 combat examples the main factors were:
The cavalry were of better quality: 22
The cavalry were armed with lances: 9
Heavy cavalry broke the square: 8
Wet weather conditions in the combat: 6
It was a “multiple combat”: 4
The square was weakened: 3
The square was disrupted/unformed: 2
On the other hand, I decided that this was an opportunity to add a modifier for the effect of the supporting fire of infantry squares... the effect is the same modifier that applies normally to overlapping units.
So I have added the following combat points and die roll modifiers for cavalry v. infantry squares.
Unit class die roll modifiers:
-1: To cavalry attacking an infantry square supported by another square within 4 centimetres.
Combat points:
+1: If heavy cavalry/lancers unit die roll is a “6”
+1: To heavy cavalry v. square.
+1: To lancers v. square.
+1: To cavalry in wet weather.
