"The Theory of Bidding" by Norman Squire is a classic on bidding structures. It is not concerned with any particular bidding system, but rather with the logic of the sequences. You may invent a gadget to discover the distance to the moon but you cannot invent the distance. Analysis in depth of card structure as dealt at the table, shows irrefutably what is sound. Time and again we find that methods sanctified by tradition and employed by millions are inefficient. The right way is not invented; it is discovered. You may invent and then discard conventions but must not discard correctly discovered principles. In artificial systems authority is paramount; players are told to do this or that without question. Natural systems are different. If an author states that so-and-so is theoretically correct, he has the responsibility to supply evidence in support".