Lol dude Greb prime was back in the 1920's. If you honestly believe boxing skill and talent wise is the same now as it was almost 100 years ago then maybe you should just quit boxing. Greb was considered skill back when boxing was in it's baby stages. Compared to even the worse boxers today Greb would be considered a tomato can. So my point still stands. Even somebody like McGregor is way beyond any boxer from that 1920's.
I often wonder if McGregor was around in the 80s and he fought prime Hearns at welterweight, what would happen?
I guess this is a boxing forum, so you are looking at Greb's rules rather than MacGregor's rules, right?