1) The document describes a method for calculating the probability that candidate A's vote total is always greater than or equal to candidate B's vote total as votes are counted. It models the vote counting as paths on a lattice from the origin to the point (a,b) representing the final vote totals. 2) It proves that the number of "bad" paths that pass through the region where B's total is greater than A's is equal to a+b/b-1. 3) It then uses this to calculate the probability that A's total is always greater as 1 - the number of bad paths divided by the total number of paths, which equals 1 - b/(a+1).