The "Win Rate" is an okay measure regarding how good a card is, but it just does not seem to do it here is why:
Every game where each player buys a particular card, that will automatically contribute 1.00 toward the "Win Rate" of a card. Hence the "Win Rate with" columns really measure underrated yet effective cards and the "win rate without" effectively measures overrated ineffective cards. The question remains, how does one accurately measure just effective cards regardless of overratedness?
Here are some ideas, none of which are to be taken too serious, just bouncing ideas:
Top 100 +% (The +% but only among the Top 100 players)
Top 100 Win Rate With
Top 100 Win Rate Without
Average number of points per copy.
Average score difference(s).
Average number of Turns until first Province/Colony buy when bought
Average number of Turns until first opposing Province/Colony buy when bought
Any thoughts?