Ok thanks I think I understand that part now, next question
After having a look through your website Brian and reading over and over again.
So you can modify the electrofrog points by breaking the wires underneath and adding the extra wires across the rails.
If you do this method am I correct in thinking that a polarity switch is needed to be added into the circuit with the point motor and points switch itself such as the Peco PL13 (are there other options?)
If I do the modification is the polarity switch needed?
If I don't modify the electrofrog point is the polarity switch needed?
And if I don't modify it and there is no need for a polarity switch how do you wire up the electrofrog point to the points motor.
I will be using gaugemaster pm10 and Hornby points motors if that helps answer my questions.
This wiring business leaves me like this in all honesty so as always thanks for everyone's input.
Pete