Its very simple, it's just the number of people you follow who also follow a given person. I also took mutes into account by subtracting pow(2, log(n)) from the follow score where n is the number of people you follow who mute a given account.

essentially it generates a graph out of all of your follows, and their follows follows, and their follows follows

it walks the graph and computes a weight for each, which technically could be a kind hamming distance, combined with a graph weighting

so to compute each WoT score it must repeatedly walk through each of your follows, check their follows, and search for a given candidate to evaluate

it's not as complicated as it sounds, but it is as complicated as it sounds

it's highly effective and honestly personally apart from irritating problems i have lately due to refusing to use free relays coracle's automated filtering is amazing