The Bridge concepts of balancing , trapping and D.S.I.P. (Do Something Intelligent Partner) competitive double theory is based on wasted values in the opponents trump suit. Take these two hands 
Jxxx 
Qxxx 
AKQx 
x , they open 1 to your right . What do you bid ? 99 % of Bridge players will pass as they do not have a good bid with the bulk of their HCP’s wasted in the opponents long suit. Change your hand to AKxx AQxx xxxx x and you have essentially the same HCP’s but this time no wasted values in diamonds. I believe in trapping when you hold the opponents suit with wasted values . However , when you do not have wasted values , I would double with this hand . Playing equal level conversion , I would scramble to 2if partner bids 2.
Do not trap when you just cannot figure out a bid especially vul vrs not. A trapped hand in today’s game is a descriptive call. The concept of trapping shows wasted values in the opponent’s suit which diminishes the hand’s offensive potential. Like in negative double theory , partner will bend over backwards
with quick tricks to double in the balancing seat to “protect” your pass. One level doubles converted can be simply brutal for the opening side especially when they are prone to opening garbage.
A Tormentee held a hand that everybody was getting into trouble.
AQx AKQx void Jxxxxx , you hear 1 to your right. This is the wrong hand to trap as you do not have wasted values in clubs. You do not have a book bid , but passing should not be an option. The reason why you can get away with trapping with some big hands is that you have wasted values .Generally your side can not make anything & they go down a bunch. With this hand , partner may not balance with hands that can produce a major suit slam & they still can make 1 their way.
Give partner J109x xxxxxx xxx void & you have a shot at +1430 or even a grand slam in hearts . Give partner Kxxxxxx xxx ♦xxx ♣void & you have the same slam opportunity as they are making 1♣ !! Passing & backing in later is not the way to describe this hand . You may not get a chance to back in as 1 can get passed out or they find their diamond fit so get the auction up to high levels too quickly for you. Passing and backing in later should show a club suit trap i.e. wasted values in clubs not just length in their suit.
The Tormentee overcalled 1 , I made a negative double so they bought the hand in a heart partial. We lost 13 IMPS as everybody was getting into trouble with contracts ranging from 5 in their 6-0 fit to 4XX for –1000. Sometimes you must manufacture a bid when passing is a poor alternative. This is hand evaluation pure & simple. You do not trap without wasted values in the opponents suit. A heart overcall was the best & winning bid by the Tormentee. Fixed again J . It hurts less when you are fixed by a Tormentee though.
