Thrump Double

Thrump doubles are a concatenation of “THRee notrUMP” doubles. They are used when your partner opens and RHO specifically preempts 3//:

Partner     1

Opp 1     3

You     ?

Opp 2

Partner     1

Opp 1     3

You     ?

Opp 2

Partner     1

Opp 1     3

You     ?

Opp 2

This situation normally calls for a penalty double or negative double, if you happen to play them through the 3-level. However, the philosophy behind thrump doubles is that probing for 3NT is more practical than showing a 4-card major. Thus the thrump double shows a balanced 10+ points that asks opener to bid 3NT with a stopper in the opposing suit.

The thrump double denies a 5-card major if responder has the opportunity to bid 3/. but chooses to double instead. If opener has bid a 5-card major, then the thrump double also denies 3-card support for partner's suit.

		Opener			Responder
		KT876			92
		A943			QJ5
		AJ3			542
		Q			AKJT8
		Opener     1 3NT (2)		Opp 1     3 All Pass	Responder     Dbl (1)	Opp 2     Pass

1. Thrump double, showing 10+ points, no 3-card support or 5-card major.
2. Promising a stopper.

Playing negative doubles instead, you might be forced to pass or bid 4. Either action would put partner in a very difficult spot.

The drawback to thrump doubles, however, is that you can miss 4-4 major suit fits:

		Opener			Responder
		KT876			A2
		AQ43			KJT2
		AT3			54
		9			QJT83
		Opener     1		Opp 1     3	Responder     ?	Opp 2

Here you would be happy to make a negative double and find your 4-4 heart fit.

On rare occasion, you can use the thrump double as a waiting bid with a big hand. You may have an enemy stopper and interest in slam, but no other suitable call.

Thrump doubles were created by American expert and teacher Marty Bergen.