Look at the pictures in this posting from Steve Hogg's site:
https://www.stevehoggbikefitting.com...ion-smp-seats/
As stated above, there are many factors that affect saddle comfort, but generally speaking, unless you're sitting erect on a three-speed bike, your weight should not be entirely on your sit bones. Depending on your flexibility and on how aggressive a riding position you take, at least some of your weight should be forward on the pelvis between the sit bones and the pubic bone. There are a variety of saddle adjustments that can accomplish this. In my particular case, I started experiencing sit-bone pain earlier this year on longer rides. Tilting my saddle back two degrees completely eliminated the problem.