In Madden's Overdrive, why do much stronger teams lose to much weaker teams

Every time I play Madden's Overdrive, I'll lose six to eight games in a row to much weaker teams.  My power rank is 1490 and today I lose six games to teams with 3 to 5 times less power.  One to a team with a 30 ranking!  This is ridiculous.  And I almost always lose to teams that are twice as powerful and only once have beaten a time with five times as much power. Does anyone else have this problem?   It's annoying to this player but also a bad business practice because there is no incentive to increase power if power rankings have no real influence on the outcome of so many games.