I found this sketch by one of my favorite painters: Joaquin Sorolla y Bastida.
What is really remarkable about this piece is something that only advanced painters pay attention to. It is brush efficiency.
Efficiency is the ability to avoid wasting resources.
In this case: time, energy, paint. Sorolla did roughly 100 brushstrokes to capture the scene. This is not much.
It is a simple logic: Why should we waste anything, if we don’t have to?
We should not overlook the high skill level that is needed to archive something remarkable with less effort, material or time and at the same time without losing quality. It’s an amazing, hard-earned skill.