This is basically the equivalent of elo hell in the new ranked system.
By putting this "win 2/3 games" requirement, players are required to bet that 2 out of 3 times they'll get a half-decent team with no noobs, trolls, or feeders.
I lost two games due to both times bot and mid feeding (you know, double kills before the minions even spawn?) and I won one where there were two afk's on the enemy team.
And here's the thing: I can't exactly carry my team 1 to 5, as some people would recommend. I tried doing that in a custom vs bots when I was fed 60/0. It still failed, because I got out-DPSed by the enemy team and instakilled.
Meaning, no matter how good I play, if I don't get a good team, it kind of makes the whole system useless.
And if someone crappy gets a good team, their rank just shoots right up.
There needs to be some way that determines individual performance and can award points/ division series wins based on that, rather than solely considering wins and losses. Just my two cents.