S is the station's existing spin, LV is the player's line velocity, and Z is the zone in which the station is located. If the LV of the player causes spin in the direction opposed to S, the LV is considered to be negative.
Spin is also affected by Beck's Coefficient, token loading, spoon and knip, and the handedness of the station as discussed in the IMCS 1992 ruleset, points 1003.ii,ii and v, 2127.i and ix, and 5006.xix.
[TUA]
Recent studies indicate that spin does not decay, except in quadrant five and during games of Political MC.
[SM]