how do they rate how many points to give when u win a game of yahoo spades.. the points are always different?

Answer 1

the amount of points won depends on many things ....
: the sum of rates at the table
: the amout of games played on each profile.
: the wins loss ratio of each player.
: the amount of games played.
The max amout of points that can be won is 32
The max that can be lost is 64.
This is why you will find most advanced players prefer the play EVEN tables. If the big rates lose to someone with a low rate, they lose they lose big.
The average rating of each team is computed. A standard one-on-one rating calculation is made using these averages. Each player's individual rating is changed by the result of this calculation. The one-on-one rating calculation is the same as that used in Chess.

When you sit your table, add your Ps rate with yours, then add the OPs rates together, find the difference. If the difference is over 200 and you win you win max points

The yahoo deals are very kind to the lower rated player, and the player with more loses then wins on their profile.

http://help.yahoo.com/l/us/yahoo/games/play/ratings/play-03.html