The ranking system in FIFA 10 is basted on a point scale, with points being rewarded after games not only in consideration with whether you won or lost, but also how you performed overall. Below is a list of all the factors which affect how many points you are rewarded after the match.
- Amount of Goals Scored
- Amount of Goals Conceeded
- Possession Percentage
- Pass Completion Percentage
- Tackle Success Percentage
- Percentage of Shots on Goal
This isn't a definite list, as EA have not specified what exact factors determine the amount of points rewarded after the conclusion of a match, but those listed above are what we can conclude from experience.
Because points are rewarded in consideration with both the result and your overall performance based on some of the factors listed above, it is tough to say how many points you will be rewarded for certain games. For an overall, well won game, I would say that you can expect to be rewarded 50-60 points or so. Loosing games, you aren't deducted the same amount you received for winning, maybe 15-20 points deducted from your total if you loose a game by 2 goals or so and didn't play particularly well. For ties, you should receive 10-20 points if you played alright.