Every fan base has a small minority of knowledgeable fans who can name 30+ players on the current roster and a large majority of casual fans who can name about 5. Does it really matter if the "knowledgeable" fans compose 2.1% of one fan base and 2.2% of another? Whatever the real numbers are they are very low for every team.
What most people are thinking of when they are talking about "best" fanbase is really just the fanbase with the highest demand for goods from that team; merchandise, tickets, TV/radio broadcast, internet clips. To be a comparative statistic it should be normalized by income and I would further argue it should be normalized per capita. Best and Most are not synonymous and can be talked about separately. Prices should not be used to estimate this because they include supply-side effects such as stadium capacity.
What most people are thinking of when they are talking about "best" fanbase is really just the fanbase with the highest demand for goods from that team; merchandise, tickets, TV/radio broadcast, internet clips. To be a comparative statistic it should be normalized by income and I would further argue it should be normalized per capita. Best and Most are not synonymous and can be talked about separately. Prices should not be used to estimate this because they include supply-side effects such as stadium capacity.