When I completed my placement matches, I was put into plat 3. I then managed to work my way up to plat 4. When I got to the semi-finals of one the matches, it ended in a tie. The other player gained the win and I lost 93% of my rank. I'm pretty sure that's not intentional, and if it is, it's extremely stupid.
I know excactly what you mean, I only reached Gold 2 but that doesn't matter. I was placed in Gold and I got to completion 74%. I worked my *** off to get to 94% and then I lost 3 games and suddenly I was at 33%. In fact the propotions of the winning percetage vs the loss of percentage when losing are insulting. I mean you get 5 to 7% for a win and a loss takes 33 to 45 % of your bar. that is just not fair. I hope that they change this for the official release.