Ok, that is a legitimate ... quibble. Let's assume that we don't already know the correct distribution. In that case we're going to judge each theoretical fit b

Ok, that is a legitimate ... quibble. Let's assume that we don't already know the correct distribution. In that case we're going to judge each theoretical fit by how close it comes to the historical data. (Or else we're going to get that wrong, which is another common approach.) ELO is much more prestigious and credible than some guy who made a game, but it is less credible than data, for some number of data points N. (Although I think a theory can be more prestigious than data almost independent of N.)