WOW: BfA Item level scaling in (instanced) PvP

When I first started playing BFA, I was under the impression that pvp scaling had been removed. The damage I was dealing to enemy players seemed to be the same as what I was dealing to mobs. At some point, I found this forum post that claimed the damage you deal is scaled up or down based on the item level difference between the players.

I gave this a test myself and realize it's true. The damage you see you've done on your side is not the same damage the other player takes.

I just tested this in a duel to confirm this scaling system is still implemented. I frost shocked a 400 ilvl warrior on my 409 ilvl elemental shaman. In my combat log, it said I did 4,431 damage. In the warrior's log, it said he received 3,870 damage. The game compensated for our HP difference by scaling down the amount of damage I dealt to the warrior.

I don't think there are any official resources out there that explain the exact numbers behind this scaling system, but the forum post linked above seems to come close enough for a basic understanding of how it impacts the game.