just so you guys know, in the gauntlet (i know this question is for champs), after 7 wins the ELO turns on and you get much harder matchmaking. so i assume the same happens in champs at a certain number. its a walk in the park for the fist portion and then when you get in range of the large scale rewards, it 1 takes longer to find a game. and 2, those games are vs better players. you will sit in that queue for 15 mins while an equal player finished their game to match up with you. but the first 10 games, it takes 10 seconds.
basically i think for champs this turns on at 12-14 wins and for the gauntlet it's at 7-8 wins