when your balancing the tonearm you set the anti-skate to zero! Then once you have balanced your tonearm and set the tracking force, then you set the anti-skate to the same number as your tracking force! So, if your tracking at 2 grams, you set the anti-skate to 2!
If you try to balance the arm with the anti-skate set anywhere other than zero it will pull towards the center of the table!
Mr. Scott Fitlin