Genetics matter for only two aspects. One is your muscle insertions depending on your height, and the other is drug response.
You can sit there and tell me all day long that a natty can get to this point or that point without any "help." But anyone thats tried the natty route with a bodybuilding perspective is never satisfied with that..you can be lean as a natty yes and even veiny...but thats the end of it. You will lack depth in the muscle, maturity in the muscle, volume in the muscle, and overall thickness...there will be no pop.
Now muscle insertions create a look that is appealing to the eye. That is usually one that is not boxy. It encompasses one that has a small waste, with a large upper body, usually big chest shoulders and back. Ofcourse arms come in (arms depend alot on drug use). Now the legs need to be there to balance it all out and some are gifted in growing these things and others depend on oil use. Thats the only genetic factor, structure...but as i said a natty will only go so far... certainly not enough for an actual body builder...
Now the other aspect is drug use...the only genetic factor is how you respond to the drugs you use. Id say it probably doesn't even matter what you use...a cocktail of things all around from combinations of aas, including hgh, igf, diuretics and insulin. If you respond well to these, meaning your body can utilize this with the least amount of steroids present than someone else with maximum growth..well then you are a good responder..and thats what makes champions. How you respond to these will stimulate the look of growth, leanness, fibrous tissue, maturity, and thin skin. The game changer is IGF. Bad response to all the other drugs? use quality igf and say good bye to your body not responding. This stuff will MAKE you grow in the right environment.
So when people say genetics. Its two things that make a champion. Its Drug Response and structure with respect to muscle insertions and bone structure.
I fail to see how "arms depend a lot on drug use".... i'd even venture to say drugs play LESS of a role in arm development than other musclegroups (such as back development).
my reasoning being I've seen A LOT of guys with 'good arms' with drugs, without drugs, and AFTER drugs.... it's not hard to get a developed bi/tri/brach without drugs... they may be smaller, but a 16" hard and separated arm isn't difficult without drugs.... and I've seen plenty of 19-20in arms with plenty of drugs that looked like shit, even when lean and dry.
now, how many have impressive, lean, hard, separated backs without drugs? not many... i'm talking top to bottom and side to side development. from where the traps tie in to the skull, to where they spread over the shoulder, to the center of the back, the way the rhomboids pop off and separate from the spine, to the errectors and the finger-like striations the spread from the spine, to the 'lower lat' shelf that jumps off the obliques, to clearly defined and separated teres maj/min, to wide feathery lats......... I've never seen THAT without drugs... even on guys who've had it before WITH drugs, it's not a quality you keep after removing the drugs the way you'll keep arm development after removing drugs.
I wouldn't exactly call igf1 a 'game changer'. if I had to choose between running 300mcg igf1 and running 30iu gh... i'll take the gh. (even though I do use igf1 in the 150-200mcg range)...... i'd say increasing the overall AAS dosage to the 4-5g/wk range is more of the 'game changer' than igf1 or gh.
now... the way your body utilized those drugs is dependent on your genetics.. no matter how many SARMs you use.
for instance, i'll put a number to my 'theory'... on a scale of 1-15, guy A may get results of 6 on 2g/wk, and guy B may get results of 9 on 2g/wk.... now, for guy A to get results of 9 (same as guy B), he may require 4g/wk. now, give guy B 4g/wk and he may get results of 14.... and give guy A 9g/wk and he may only achieve results of 11, no matter how much he uses.
if any of that makes sense.
some guys just don't have the cells... some guys just don't have the androgen receptors... some guys have plenty of both (think Dennis James or paco bautista or Ronnie coleman or dorian...... I don't think Flex fits in that group, since he had 'baby' muscle except for his arms, despite his 'myostatin deficiency' claims)
this is bodybuilding.... it's illusion, mostly.
take flex's back, his teres and rhomboids were separated and it drew your eyes to the center of the back, giving the illusion of width... but his lats weren't wide and thick at all.
.... i'm rambling and lost my train of thought.. i'll come back to this thread later. gotta staph infection/abcess lanced last night and the pain meds are making my nauseous .