I'm gonna go super-geek nerd analogy here, so if that floats your boat, keep reading.
My educational background is in Controls and Dynamics, a subset of engineering used in various applications, most notably robotics. The key idea behind controls is to control something (talk about a big reveal). As a simple example, say NASA wants to launch a rocket to Mars, but to conserve fuel to make it to their destination, they need the rocket to travel at 300 miles/second (note: these numbers are completely fabricated). No faster, no slower. The rocket speed is controlled via a propeller (note: rockets do not use props for propulsion, they use rockets, but for simplicity's sake, we're using a propeller).
After launch, a good control algorithm (e.g., nonlinear, adaptive) will adjust the propeller speed in such a way that we quickly get to our desired cruising speed of 300 mi/s and stay there. The problem with these algorithms is that sometimes they can screw you and go out of control (and there ain't no coming back when that happens). Safe algorithms (i.e., linear: pole placement, PID, etc. -- warned you this was super geeky) will always get you to your speed, but usually they will overshoot and then fluctuate around your desired setpoint (300) before eventually settling (a dampened sine wave).
A writer's arc is in many ways analogous to a control algorithm. We don't hit our desired setpoint right away, usually. We tend to overcorrect based on feedback, rules, etc, but eventually, if we iterate enough, we can find our setpoint.
PS - I'm off the grid at the moment (hopefully somewhere in Yellowstone not getting eaten by bears).