Is it acceptable to consider probabilities within high school?

I’m applying to Stanford freshman early action. My chances don’t seem low, but I’m considering the probabilities of competition within my school. The chances of more than 1-2 kids from my school getting accepted early action to stanford is very slim based on history. I already know two kids who are most likely more qualified than me. Even though the admission is independent of school, is it acceptable to think of my chances in these terms?

No it is not acceptable. You appear to be looking for excuses for a possible denial or deferral.

I think it is practical to consider, which implies starting on all your regular admission applications, essays, etc as well as finding other schools you would be happy to go to, including a few safeties.

It might not be acceptable to dwell on this in public at school … I remember hearing rumors in high school about how I stole the spot of someone at Cornell … and was not happy about it. If they get in, great, if you get in, obviously better for you.

There are lots of good schools and if you are a good candidate, you will have a good place to go next year. Just plan for all possibilities.

Worst case you can tuck all those essays into a nice binder and enjoy Christmas with that acceptance letter, better candidate is defined by Stanford, not you or others.