Dr b gave me 900 free grafts in op 2 to re densify and tough up areas of op 1 so I figure he felt I got about 70 percent yield. But really who knows. Did I get 60, did I get 80 who knows. Dr b stands by his work and gaurantees minimum 90 percent yield. We really don't know why the lower yield in op 1 as the op went extremely well . Dr b however wanted to do the biopsy to rule out any potential skin issue. As mentioned above my result came back that my scalp is compatible with lpp which causes inflammation and attacks follicles and kills them. Although I highly doubt I have lpp, dr b recommended the clobetasol shampoo to control inflammation. I have fair skin and although healing from op 1 was great, I Recall my scalp being red for a few months post op and definately likely had prolonged inflammation. Did this inflammation affect growth, had I taken the shampoo after first op would I have got better yield ,,,,who knows. What's done is Done and now just focusing on getting top yield for op 2. It will be interesting if yield is much better now that I will be using the shampoo. I will keep everyone posted.