Originally Posted by
fixedgitane
and both the numerator and denominator are odd, the number of possible skid patches will be doubled.
This is nonsense.
If you have both numerator and denominator even then you can simplfy the denominator to 1 which would always be true. In which case you have 1 skid patch. If you start adding qualifications like "left foot forward or vice versa" you might as well have said nothing as it's worthless. The number of skid patches haven't doubled anymore than not stopping your foot at exactly one rotation.