Here's where having a teacher helps a lot. I started out as an adult beginner, and I remember that in one of the first study books (Duvernoy or Burgmuller), there was a passage in the left hand with a sequence of six eights, it went like C-F-Bb-F-A-F. Because of the slow tempo, I could have easily done it 5-1-5-1-5-1, where my thumb would just repeat the F, and my pinky would go down the C-Bb-A sequence. This is where my teacher stepped in - he told me that this is a great learning opportunity, and I should play it 5-1-4-1-5-1, fifth finger on the C, fourth over it to the Bb, fifth to the A. The main reason was that this would be more comfortable at higher speeds, but also that it would allow to do a finger legato on the sequence of three notes.

A lot of the fingering remarks at this stage were about legato. In the easy Beethoven Sonatina in G, you have sort of a reversal of my earlier story - the downward movement is in the top notes here. There's a sequence of two chords, D-A and D-G in bar three. You could easily do both of those 51-51, but then the possibility of joining the two upper notes would be lost. The "correct" fingering would be 51-52, lifting the pinky and doing a nice legato on the top notes, one that follows into bar 4 with 53. It makes a world of difference when you hear how it sounds with a proper chord legato applied.

If you don't have a teacher, the next best thing would be to make sure you have a good edition with the proper fingerings added. Something like Alfred Masterwork, or the newer Schirmer Performance - both are relatively inexpensive and nicely edited. But then you will get just the fingering without the reasoning behind it.

Thank you very much for such detailed description and recommendation. I think "legato" reasoning is a good example for how reasoning works in general and so one can guess what correct fingering would be when there is no teacher around.

> and so one can guess what correct fingering would be when there is no teacher around

At least in some cases, yes. For me, that's the real point of having a teacher - learning the thought process, not the pieces.

One thing worth mentioning is that sometimes the correct fingering for a piece is contextualized. There are pieces that you might treat as a goal in their own right, but they might also be just a stepping stone to other pieces. For example, you might see a sequence of three notes in the left hand, and there will be a "correct" fingering that's most comfortable for just those three notes. But the teacher that suggested this piece knows that those three notes can be seen as a simplified version of a six note pattern that occurs throughout a more difficult piece you will tackle later. So the "correct" fingering they suggest to you is the fingering that's most comfortable for the more difficult version you haven't played yet. You're not looking at the piece as-is, you're thinking of it in the context of what you'll eventually play and optimizing the fingering for performance of the target piece.

You will often hear that "correct" fingering is the one most comfortable. This is only partially true when you're in the early stages. Often, you go for something that's suboptimal in a particular piece because it will be more comfortable in another piece down the road.

I think of it like a dynamic programming type situation. You have notes to be assigned fingers to and the metric is minimizing uncomfortable/awkward hand movements. So the specifics can vary from person to person (and hand to hand), but there are generally agreed upon fingerings for things like scales or chromatic runs.

>there are generally agreed upon fingerings for things like scales or chromatic runs

Can you point out to such "agreed" fingering somewhere? Because as a self learner I perhaps had no chance to know which one is it?

Here's an example fingering chart for major scales: https://i.pinimg.com/originals/20/36/98/203698fda995f78e8621...

For the chromatic scale, I was taught to alternate 3 and 1, using 2 when there are two white keys in a row.

A more generic rule I heard later on was to not use your thumb on black keys (when playing scales). That constraint can sometimes help with other fingerings falling into place more intuitively.

I learned it a little bit differently, for example

https://youtu.be/twc_Yo4LFJI

As I understand it's not different at all. Diagram shows how you play it continiously (not one octave only)

It is for me; both comfortable and clear sound; how I see and agree the correct positioning is. Emphasis on seeing how people have incorrect positioning can form bad habits. Fix these for yourself; and for your audience

Most piano books have fingerings printed, and you'll find of course that they vary between editors. In general however there will be a fingering that makes the most sense. I'd posit those pianists you asked misunderstood the question, I hope you keep at it! A friend played me for recently a piece she's been learning for a year and is just so happy, and proud of her work. It's a beautiful thing, to play music.

After sight-reading through the piece a few times you can generally start writing down the fingering on the score. Keep a pencil handy.

It's a bad idea to finger on the first play or the first day because there's a risk of premature optimisation. It doesn't take much analysis apart from one or two specific problems. The fingerings I end up with usually vary somewhat from the editor's.

But the OP is correct, once you've got a fingering, you have to stick to it, even if it's suboptimal in places. It's your fingering, and if you change something after 200 repetitions there's a danger of slipping back into the old pattern and stumbling.

This is quite subjective, but taking some time to analyze the piece and figuring out what works best for you is usually better than just doing without thinking.

I don't think it's a given that there's a single correct fingering, but it seems obvious that an incorrect fingering is one that's impossible to use at your desired tempo.

People have different sized hands, and different hand strengths, so some fingerings may be more damaging to a pianist's hands, and some might be more comfortable but break down at higher speeds, and some might simply be impractical at any speed.