Say a given sport requires repetitive production of 10 units of force and now you're capable of producing 100 units of force. By getting your maximal production capacity to 200 units, your submaximal tasks go from 10% to 5%. When you get to 300 units, your submaximal tasks will go from 5% to 3.3%. I believe this is the asymptotic approach Rip is talking about.
And we know that going from 100 to 200 is easier than going from 200 to 300. We also know that after some point, increasing strength will only be possible if we borrow recovery reserves that are allocated to practicing the sport. That situation represents beginning of specialization in a barbell training.