There's a reason I prefer "lots" over "infinity". For your "quicksort of 4 elements" example, I would note that the algorithm doesn't care - it still works - a

There's a reason I prefer "lots" over "infinity". For your "quicksort of 4 elements" example, I would note that the algorithm doesn't care - it still works - and the choice of when to switch to insertion sort is a mere matter of tuning thresholds.