I think that Mentzer's early 4 day routine was his best for pretty much everyone. It is unreasonable to expect results every workout unless you include the one thing that truly separates us from them. Drugs. There is what is known as an "effective dose" for pretty much every drug made but it could be said that there's "effective" and then there's "ridiculously effective".
The latter one is probably based upon an individual's response and given the recent death of the idiot known as Dallas McCarver, more often than not exceeded a thousand times over by the idiots from the era of Dorian Yates on. Arnold obviously knew his. Mentzer too. The guys in the 70s at the top of the game each knew what worked best for them and not to exceed it because not only the diminishing returns factor but also because they didn't want to mess with their future because no one really knew what to expect down that road. To know that just look at Coleman. What a fucking retard.
The thing is to get the most from not so much the least, but rather what's best for each of us. Mentzer's 4 day split probably does that for more people than anything else out there, especially natural trainers. You may have to tailor it to your body with sets/reps being the key, but once you find the combination that opens your door you're on the way. Having said that, don't fixate on just one path but shakes things up every once in a while. The mind controls the body. Use less weight and more reps or more weight and less reps. Take a week off or train an extra day.
It's just training and there's more to life outside the gym than in it. Mentzer showed us that truth. Too bad he didn't stick to that road. He might have lived not only a longer life, but a happier and healthier one.
