On: The Knapsack Problem Is All Around Us

[Jedd]

> It converged upon a dramatically better solution in a few seconds, and didn't really improve it in the next few minutes.

Which in turn is, I think, a manifestation of the Secretary Problem.

https://en.wikipedia.org/wiki/Secretary_problem

[karussell → Jedd]

I think this is more the general behaviour of heuristics. They are not guaranteed to give you the optimal solution as they are forced to 'converge'.