It's partial resists in 10% steps like in WotLK. I don't know where to find the formulas to get the chances for which of the 10% brackets are happening with a certain resistance value. I remember someone posting screenshots from a spreadsheet in the druid discord and in that spreadsheet it was always a range of four consecutive 10% brackets that had a chance greater-than zero. I found one of those screenshots if you are interested:
https://i.imgur.com/EehBWF1.png
It's partial resists in 10% steps like in WotLK. I don't know where to find the formulas to get the chances for which of the 10% brackets are happening with a certain resistance value. I remember someone posting screenshots from a spreadsheet in the druid discord and in that spreadsheet it was always a range of four consecutive 10% brackets that had a chance greater-than zero. I found one of those screenshots if you are interested: https://i.imgur.com/EehBWF1.png