I guess I'm not quite seeing what you're seeing. Each curve can be broken up into a series of patterns, and I've tried to describe the patterns (for Fighters, and I've also done it for Thieves, the rest not yet). Since the patterns are not constant across the whole curve, I've done it piecewise. The status bonuses (as I've called them) are not the actual bonus, but rather a "guarantee" that it will increase. Even if it's false, there is a 50% chance of increase. So it's actually a series of 50% or 100% chances of increase.