Sauron is not showing is ugly little head

[KesTheHammer]

I had to get the ring from him in Angband 99, went to Mount Doom, he was not there - so I destroyed the ring and headed back to Angband.

I have been up and down angband 99-113 several times, and he is just not there.

Questions:
1. Do I have to wait the X turns before leaving a level, to avoid the "normal level" feeling?
2. Do I have to keep going deeper, or is going back and forth between 99 and 100 fine?
3. What is his likelihood to show up?

[Estie]

Isnt it lvl 99 only ? At least I used to always reload that level till he showed up.

As for resting to get better level, I am not sure either. If there arent any special rules regarding Sauron, it should be more likely to get him after resting (since he is a high level unique and adds to value), but whether that is enough to justify the time wasted resting, who knows.

He can take his sweet time to show up; my method was to go up/down the (connected) stairs between 99 and 100 till he showed up in ESP (look at the visible monster list).

[Yottle]

Sauron will eventually show up at any level 99 or greater in Angband. It can take a while- I guess 20 levels is not unusual. I turn off my brain and stair-scum.
If he doesn't show up you need to make absolutely sure he isn't on the Mt Doom level.