Don't trade the same pair all the time....

I have been involved in Forex trading for the last couple of years.Like most of you here, i am in the search of a perfect system that will help me to increase my success in trading. Most of my time i am busy testing systems, entry-exit points, money management etc.
Now let me go straight to the point. Since day 1 in my trading journey, i hear and read:" Focus on 1 pair only. Learn the characteristics and master how this pair behaves on certain circumstances..get familiar with it.."
Excuse me?? learning the future?? BS..No such thing..
Trading is all about probabilities. Nobody can see where the pair will go, not even within the next 10 minutes.
Instead of trading only a certain pair i am focusing for the last few weeks on the strongest vs. weakest currency in the market. After determining these currencies and with the right entry points, trust me, your success will increase.
I am not re-inventing the wheel here. Just trying to focus and point something, that we usually ignore...
Any comments would be appreciate..

And how are you ascertaining the relative strengths of the currencies?

Well, to determine current weeks Strong-weak currencies, you can either do manual crossing on major pairs or use Strength Indicators. One of my favorites are Kang Gun's Rs Group indicators.

Just set up KG's indie. But what moved first--the indie or price?