You'll need to study statistics a bit to fully grasp the concept (see
http://en.wikipedia.org/wiki/Standard_deviation).
Basically, spar ratings in Graal work like this:
NPC Code:
(recent wins VS recent loss)
over
(recent # of spars)
Except, each is weighed a bit.
updateratings and
updateratingdevation don't work on a player object, they only provide a means to "emulate" a spar win or spar loss on a player, and return the values which you then set on the player.
The cool thing is that you can even simulate a 3-person-spar or a 4-person spar with that.
To simply set the rating / rating deviation on a player:
PHP Code:
player.rating = 1500;
player.ratingd = 350;