There have been a few posts in other threads, some of it is the WR of other teams you play, but there are a couple other factors as well.
-Losses can help if they're against a significantly better team
-Cup games are heavily weighted, especially as you continue to go deeper into the Tournament, you'll find your WR rise exponentially
-Home/away games make a difference
-The skill of the team your opponent puts on the floor matters as well. A win versus a top-100 team doesn't carry as much weight as normal if they only play their backups. Likewise, if you beat a team ranked 30000 who has recently loaded up on a bunch of 100k+ players, it will carry significantly more weight than playing your normal team ranked at 30000.
-Kind of going off the Cup games point, there's a huge benefit to playing meaningful games when others aren't. Consider your World Ranking to be something of total points gained (for example- you get 2 points for a win, and 1 for a loss). Say your WR is 1000. Meaningful Cup games, and postseason games both offer the opportunity to gain points when other teams are playing scrimmages (which don't help WR). In this example, even if you eventually lose late in the Tournament, or in the postseason, you're still gaining points when many of the teams above you are stagnant- offering a great chance to move up
Hope this helps a bit.