They're Gonna Be Close. Remember, against competent opponents, every hand will be close to the theoretically correct bid. When opponents chose to defend or declare, they are evaluating their hands as well as possible given the bidding they hear. You Gotta Be Close. You must do the same, and you must, of course, temper all these decisions with the scoring possibilities -- vulnerability is always foremost.
There is a bridge theory called the Law of Total Tricks which is worth understanding when you get deeply into Duplicate. It relates to the theory of competing auctions when both sides have a fit, and is a must for advanced Duplicate players. It's not included in this series, however. Hands and Gloves. Hand evaluation and balancing are hand-in-glove concepts -- the reason to work so hard at hand evaluation is to determine whether to balance, defend, declare or double in close contests.
Bridge doesn't get any better - after all, it's only a game.
(c) Robert D. McConnell, 1998 All Rights Reserved