Here's an excerpt from an article discussing the FFMI (i.e., the fat free mass index) that was created to statistically determine who is likely beyond what's possible naturally. 25 is thought by many to be the natural limit, but some think 26 and maybe 27 might be possible. From the article: ". . . [regarding] the men’s top ten finishers in this year’s CrossFit Games (2017), six of the top ten are in the 28-30 range [of FFMI]. The other four are in the 26-27 range. It’s worth noting that I don’t actually know their respective bodyweight percentages, but I generously estimated them all at 7% (which I think is generous)."