Originally Posted by MikeM
However, if you NEED perfect form to hit any given lift at the maximal range then you are somewhat form dependent. So, if you back off a little bit, work on hitting that weight more and more often, you will be better at hitting that weight under non-optimal conditions or imperfect form. Therefore you are stronger.
Mike, I still don't necessarily think what you're describing is a result of more/less strength. I think your struggles with single rep maxes relative to rep maxes are more a matter of neuromuscular efficiency.
I've pretty much always trained with low reps and as a result I'm highly efficient and the disparity between my single rep max and rep maxes are massive. Whereas someone else might be able to do a set of 5 with 90% I would be very lucky to get a triple for example.
People used to consider this a matter of muscle fiber make up, but I think that was too simplistic an explanation to be accurate, your body will just adapt to what stress you put upon it. Constantly heaving up singles will get you better at them and over time (6-12 months) you will find your ability to do reps will diminish as your ability to do singles increases.