PHost creates a file, score.log, which logs the standard score. This is a very simple score computed follows:
Score = Num_planets * 10 + Num_capital_ships * 10 + Num_freighters + Num_starbases * 120
A capital ship is one having at least one weapon (could be an Outrider with a Laser, or a Death Star armed up to the teeth).
Many client programs can also display this score. They compute it from the Num_planets etc. values reported within the result files. If ScoringMethod is set to None, PHost does not send these values, causing clients to report the scores as zero.