After finding such high yield try doing  3 months back engine only and compare to "known" settings.

Now put those settings on bitcoinwisdom graphs and see if those long term high yielding setting are actually valid or is there another reason for such high returns?

I have noticed the settings I found to be +19K% would have bought at higher prices and sold at lower prices than another setting I use. But if I had gone on with the 1 year engine, it would have led me to believe that  settings I would have actually made more profit in the last few months are actually less than half as profitable than the one yielding much lower returns in the last few months.
Did that make sense?