Variants reduction is done by selecting the variants from the .csv file with the chosen ”n step”.
E.g. step n=2
Out of the 1,2,3,4,5,6,7,8,9,10,11,12, ... variants from the variants file you have selected, there will remain the 1,3,5,7,9,11, ... variants.
E.g. step n=3
Out of the 1,2,3,4,5,6,7,8,9,10,11,12, ... variants from the variants file you have selected, there will remain the 1,4,7,10, ... variants.