Problem finding track direction using polar stereographic
I'm having big problems finding track direction using a polar stereographic chart. I find that the 'laws' which work on one example don't seem to work on another. It all seems very messy. Ive even drawn diagrams of the damn things. I can work out convergence no problem. But I can't decide whether to add 90, take 90, add 270 or take 270 away from the convergence angle.
Can anyone help me please. I don't understand why a given track heading east is classified as heading west at the mid point on the polar steorographic and vice versa. Are there any rules that help. Please don't anybody refer me to Oxford's notes thankyou!