Whenever mathematics types get asked why cords get tangled, they sometimes answer “because there are many more tangled states than untangled states, so a little bit of energy is much more probable to dump it into a tangled state.” (much more complex exception)
But that can’t be right, because the it confuses messiness with difficulty to leave. Doubtless there are more “messy” than “neat” states of a cord, but an arbitrarily messy cord doesn’t count as “tangled” unless you have to struggle to get it out. And there’s no a priori reason to think there are more tangled than untangled states.
That observation, however, points the way to the correct answer. Because tangled states are much harder to leave, at any random time over the life of a system that’s getting energy put into it, we’re more likely to observe one. No matter what how many tangled states there actually are relative to the number of untangled states.
To see this, imagine a cord with 20 possible states, 19 of them taking an energy of X to leave (the untangled states), and the 20th (the tangled state) taking an energy of Y to leave, where Y is much larger than X. Now suppose that the cord is subject to a shock every second, normally distributed, where X is the mean and the standard deviation is (Y-X)/3. And suppose that once the cord leaves a state, it picks a new state to be in from a uniform distribution of the 20 possible states.
It’s pretty obvious that it’s going to end up in that tangled state pretty quickly, and stay there for a long time, isn’t it? Just because it takes much more energy to get out of there.
Essentially, this is the same abstract-level idea as evolution. Stable states get observed more than unstable states just because stable states tend to stick around long enough to be observed.