The 3 x RSI gives you the ability to plot the RSI of 3 currencies of your choice into a single indicator. In addition it allows you to plot to Moving averages of the combined RSI on the same indicator.
The best choice of the 3 currencies are ones that are inter related for eg:
1. EUR/USD = EUR/GBP x GBP/USD
2. EUR/JPY = EUR/USD x USD/JPY
This indicator shows you the strength of the entire ring as the 3 pairs move forward in time as a single inter-related unit.
This gives you that little early edge.