Richie0613:I calculate distance, wind and elevation in my head. Figure on type of spin to use and move my aim to a best guess if left or right of the hole just like a PGA player would do. That is how the game is designed to be played.
That's what I do too. All the math and trig and estimation is done in my head.
But to answer your original question: Yes, it is very possible for players to shoot low scores (eg. 55 in a round) doing that, playing without tools of any sort. My last 18-hole round was a 55 (on Wolf Creek, an easy course) from the champ tees with a 45 sec shot clock. And last night I shot a 27 on Erin Hills, champ tees, with only 4 dings the entire round. And, as some people have pointed out here in the Forums, I'm just a mediocre player. So, if I can learn to do it, anyone can.