How do I know what rank I'm playing at in Stadium?

Just how wide is the rank gap in stadium exactly? I have games where we steam roll through the match 4-0 and win instantly, I have matches where it's neck and neck and it's 3-4 and other matches where I'm the one getting steam rolled 0-4 with players wayyy more skillful than us.

If I'm in contender, am I actually in a contendor lobby? Or there's a chance for All star and legends to be in that game? There's no way to know because blizzard doesn't display players ranks in the game.