1. Calculate (B-L)/(H-L)
B = current bid price
H = Period high
L = Period low
2. The result from step 1 resolves itself into a value between 0 and 1
3. Re-scale into a value between 1 and 10.
4. If the currency is YYY,
For XXX/YYY pairs
Subtracted 3
For YYY/XXX pairs
Add 3
5. Average