Is concentration risk valid if you are really good at what you do?

I found a great Real Estate Agent who specializes in REO which is what I want to concentrate on.

True, but if you concentrate on those that are unfinancable (gutted kicthens, etc.) and/or those that have been on the market for 120+ days, you can often get decent deals.

Concentrate on the positive features of the property. 

Considering the area that I have to assume from what is posted, the only real reason to bring religion into the conversation, especially in limiting the area of concentration, is on that brings up concerns of a cult nature.Those who participate in these practices also discriminate in several areas.

I'd concentrate of the Commercial Realtor courses, local business college courses and get with a mentor in you area that has done deals you're interesed in, but maybe does something else now, that way they are not in competition with you.

If the answer is zero, then I would concentrate on doing one and see how much work that is.

Or I am going to concentrate on higher end homes.

I know some people doing flips in parts of Orange County and LA, but we personally concentrate on holding and renting.

If I were starting off again, I would concentrate all of my attention and efforts to marketing for properties.