One of the first pages of a piano lesson book contains an image of the hand with numbers assigned to each finger. It’s a way to communicate a part of piano technique through text. The next pages include exercises of finger patterns that later move into full songs. For the first few books, finger numbers sit under every note. From the author’s perspective, writing fingerings down is part of the process.
From the student’s perspective, however, these numbers are just a crutch that professionals don’t use.
For as long as I’ve been in the music world, young musicians perpetuate the idea that “real musicians” don’t need these. Perhaps this is due to a flaw in the teaching system, but that’s a discussion for another time. It’s true that more advanced sheet music is not printed with these guides, but they’re still imperative to the musician’s success and leave room for individual hand anatomy to be taken into account.
Frederic Chopin is known for much of his work being in keys full of sharps and flats. These are typically regarded as “more advanced keys” since they’re a little harder to read. Chopin’s work feels good to play, once the work of figuring out all the accidentals is done. His music possesses an innate understanding of the patterns of keys compared to the shape of the hand.
His legacy shows us that some fingerings are better than others. It’s an art form in itself. It’s better to figure out the patterns, write them down, and then learn them than have to puzzle through and learn a multitude of patterns until the “right one” is reached.
A little preparation goes a long way, especially in the professional world.
There are a few books on the art of fingering, but the one most recommended is Natural Fingering: A Topographical Approach to Pianism by Jon Verbalis. This one bases its suggestions in Chopin’s philosophy of proper piano technique. I have yet to read it, but I look forward to checking it out.