Content doubts

HI blackhatters

I am making some new sites, I know the ideal scenario is putting unique good content, but I will try publish a site only with good rewriten content.

So my exactly doubt is, if a find an article, I rewrite it and make it 50% unique, and when I check with copyscape I get no results, does it google take it as 100% unique content?

I mean if I put a unique article with 0 copyscape results, will I have exactly the same good results in google than if I put the rewriten one 50% unique with 0 copyscape results?

I hope you understand what I try to ask.

I Would like to know an opinion of experienced members in this area.

Thanks in advance, and sorry my poor English