Whatever the logic your martingale is, it definitely will not work in the long run UNLESS, you have unlimited supply of capital. Been there done that. Lesson learnt.

Martingale EA. Almost can't lose!

There are no "best" pair to trade. For myself, I like volatile markets. So I'd usually trade big markets like USDJPY, EURUSD, GBPUSD, AUDUSD. You can trade smaller markets but it will be less volatile. Cheers!

The best Pairs to Trade?