Sunday, May 23, 2004 12:08 AM

D.S.I.P. - Thrump Doubles

PITBULLS:

Playing negative doubles thru 4♦ brings in the concept of D.S.I.P. Doubles (Thrump ) at the 3 level. One of the objectives of pre-empting is to get you out of your nice 3NT contract to an inferior contract such as 5 of a minor. Marty Bergen invented the bid which means a double at the 3 level asks partner to bid 3NT with a stopper in the opponents suit otherwise bid naturally. If you open a major and the pre-empt is in the other major the Thrump double really makes sense even if not playing the convention. Conceptually the double is a “western Q bid” asking partner to bid 3NT with a stopper in their suit.

1♠-3♥-? ♠x ♥xxx ♦xx ♣AKQJ10xx do you really want to bid 4♣ when a double asks partner to bid 3NT with a heart stopper ?

!♥-3♠-? ♠xx ♥xx ♦AKxxx ♣AQJx do you really want to bid 4♦ when a double asks partner to bid 3NT with a spade stopper ?

1♣-3♦-? ♠AKxx ♥AKxx ♦xxx ♣xx double as D.S.I.P. and if partner bids 3NT with her 4 card major live with it.

Thrump doubles also work when they pre-empt in the sandwich position . If you have a good hand with a stopper , just bid 3NT on most vulnerabilities. If they are vul & you are not , you can have the partnership understanding that the double is penalty. It makes no sense to have a penalty double on the other 3 vulnerabilities as partner will re-open with a double with any excuse.

The problem with Thrump doubles in general is when partner opens a minor rather than a major and they pre-empt at the 3 level. You can still double with the classic negative double looking for a major fit but partners first obligation is to bid 3NT with a stopper in their suit rather then bidding a major . This means that you are in 3NT instead of your 4-4 major fit. No big deal as with the distribution around the table the major is probably going to break 4-1 anyway.

Another problem is you do not have the “trump fit” inferences anymore . 1♦-3♥-X-P 3♠-p-4♣ this bid does not imply a spade fit and showing the club ace looking for slam . It means I have clubs and we struck out trying to get to 3NT. A double of their pre-empt at the 3 level by responder ( opener needs a rock ) can be totally D.S.I.P. . I have a flat 14 HCP’s and no stopper in their suit so I do not know what to do . Bid 3NT or pass or do something intelligent based on the vulnerability !!

The thrump double works when they pre-empt in the sandwich position also . A double is always a Thrump D.S.I.P double at the 3 level. There are various ways of “pre-empting” in the sandwich position. If the opponents make a jump raise in the sandwich position , a double at the 3 level is a Thrump double . 1♦-1♥-1♠-3♥ X or even after a 2/1 . 1♦-1♥-2♣-3♥ X . Remember they are trying to get you out of your 3NT game ! Some partnerships can modify this understanding depending on the vulnerability.

The Bergen invention of a thrump double is just a variant of the D.S.I.P. double . The first intelligent thing partner should do is bid 3NT or pass with a trump stack !

A D.S.I.P. double at the 3 level should always have “western Q bid” overtones to it. BJ Trelford had 18 HCP and a balanced hand against the Bartons. They were vul and we were not . He opened a minor and they overcalled a spade and made a negative double. RHO leapt to 3♠ so what should the opener do ? A double is appropriate with the balanced 18 HCP or a long suit requesting a 3NT bid. With 18 HCP’s you are requesting partner to do something – preferably intelligent. Against Tom Gandolfo , BJ held ♠x ♥A ♦xxxx ♣AKQJ10xx and BJ opened 1♣ and LHO bid 2♠. I bid 3♥ and Tom interfered with 3♠ . The odds of partner converting for penalty in this auction are minimal so I would make a D.S.I.P. double to request a 3NT bid. If partner does not bid 3NT , I will retreat to 5♣.

Converting partners Thrump double for penalty should be a very rare bid. The Thrump double is so variable I would only convert for penalty with a trump stack at the appropriate vulnerability. Partners Thrump double is unlimited as to HCP , fit & distribution so it is very difficult to convert.

Bergens original article below :

Thrump Doubles

“Thrump doubles,” as described here, were invented by yours truly. While they certainly are different, experience has shown that they are essential at the three level.

What is a thrump double and why do we need them? The discussion of the bidding on this hand will clue you in.

ª Q7 © Q2 ¨ 1087 § AKQJ75

Once your partner has opened the bidding, you are thinking about 3NT. In fact, I will bet that is the case regardless of which suit your partner opened. You will show your clubs and points and hope partner bids notrump sooner or later.

Nice plan. Now suppose that your RHO jumps to 3¨, 3© or 3ª before you are able to make your first bid. Are you going to give up on the 3NT contract you were heading for? If you make the “normal” 4§ bid, do you expect partner to provide the five tricks you will need to bring home 5§?

What is my suggestion? Make a negative double. However, instead of defining it as looking for the unbid major(s), think of it as looking for THRee notrUMP. On most hands where partner has a stopper in the opponent’s suit, you would like him to bid 3NT.

When is this needed? When the enemy’s natural jump overcall reaches 3¨, we cannot necessarily show our suit without going past 3NT. Here are the 10 auctions where the opponent has made a natural, preemptive jump overcall above 3§ and below 3NT.

1§ - (3¨) 1§ - (3©) 1§ - (3ª)

1¨ - (3¨) 1¨ - (3©) 1¨ - (3ª)

1© - (3¨) 1ª - (3©) 1© - (3ª)

1ª - (3¨)

Must you have a solid suit? Absolutely not. A thrump double

would be totally appropriate after 1© - (3ª) with:

ª 864 © 65 ¨ AQ754 § AQ2 or

ª 93 © K7 ¨ KQ10865 § KQ8 or

ª 63 © A2 ¨ 852 d AK10854

(Double, hoping partner bids 3NT.)

(Forget your spades. You have hearts stopped so bid 3NT.)

(Once in a blue moon you will have a great hand with a stopper in the opponent’s suit. In that case, you can start with a negative double and then explore for slam.)

Thrump Double Summary

Tells opener to bid 3NT when he has a stopper in the opponent’s suit.

Says nothing specific about responder’s holding in the unbid suits.

Almost always denies a stopper in the opponent’s suit.

Responder denies a five-card major that he could have bid at the three level.

Promises at least 10 HCP and denies three-card support for opener’s major.

Worth noting: responder could have a very long minor.