Preempts are supposed to cause problems for opponents. Sometimes they caused problems for the bidding side. One such problem arose when playing a strong three no trump opening bid. Preempts in minor suits might be predicated on any thing from a suit like QJ10xxxx to AKQxxxx. The first suit would play badly in a no trump contract. The second would likely produce seven tricks. With the advent of the strong two club bid the strong three no trump opener was no longer needed. Thus was born the gambling three no trump bid.
The gambling three no trump bid requirements are very simple: the bidder must have a solid seven card minor suit and no outside entry. It is now very easy for responder to gauge the trick taking potential of the hand. If he thinks it has a good chance of making he simply passes. If he thinks three no trump is a bad proposition he bids four clubs. Opener passes this with clubs or bids four diamonds to correct. With an interest in slam responder may bid four diamonds. This asks opener to show a singleton. With a singleton heart or spade he bides four of the corresponding suit. If he has a singleton in the other minor he bids four no trump. With no singleton he simply bids five of his minor.
Note that there is merit in bidding four no trump with no singleton and five clubs with a singleton in the other minor. When slam is not in the offering it allows the partnership to try for the game at the four level. It does require a bit more memory work, however.
On very rare occasions responder may bid four hearts or four spades over three no trump This is strictly to play and opener should pass.
The gambling three no trump bid is best played when responder is an unpassed hand.
Defensive tips: Be wary of the psychic responder at match points when the other side opens a gambling three no trump. When not vulnerable versus vulnerable and game likely for the defensive side some clever players will psych a three no trump response, hoping to intimidate you out of the auction. They figure that down nine undoubled is better than letting you bid a vulnerable game.
Also, when the auction has proceeded three no trump – pass – pass -pass, be wary of a passive fourth best lead. Declarer may be able to rise with an honor in dummy, win the trick and steal an unmakeable contract. Don’t hesitate to lead an ace or even a king in order to retain the lead, see dummy, get information from partner and make an intelligent lead to the second trick.