This Chapter of "Duplicate" describes many "standard" techniques
and some non-standard techniques of Defense.

Tools of the Defense are fewer than those of Declarer Play and
Bidding; thus, it's the hardest part of duplicate bridge.  Yet it's the
single easiest way to score better at your local club game, because
many players don't pay much attention on Defense. They simply
"take their tricks" and wait for the next hand. Players rarely spend
much time on defense compared to the hours they spend on bidding
yet we all play defense twice as often as we declare.

 But, just one trick better on defense a few times during
 a duplicate session will improve your total score dramatically. You
 can't beat every contract, no matter how good a defender you are
 But you don't need to!

 Beating a 2 Heart contract by one when everyone else makes 2
 Hearts is a top board; just as if you've scored a grand slam that no
 one else bid . . . but it's much more intellectually rewarding to the
 sophisticated duplicate player.

 Since there are so few tools of Defense, it's all the more critical that
 you and your partner are totally in sync, and that you are both
 paying attention to every card on every trick.