The origin of this conventional method is unknown. The concept behind Unusual Major Jump Over One Diamond Opening is quite effective whenever the holding requires the player to show a certain distribution of both Major suits. Many partnerships have reduced the long designation to a group of first letters to result in the unpronounceable UMJOODO.

Principle of the Concept

In the formative years of the game of bridge it was standard practice to make a strong jump shift following an opening by partner to show a strong suit and at least game values, if not slam values. This concept was promoted by all the authoritative bodies from the United Kingdom to the United States, and even promulgated and promoted in the publications of Mr. Ely Culbertson and Mr. Charles Henry Goren.

Therefore, since this action has been removed from the modern day bidding theories, the jump shift by the responder has become in general an idle and unused bid. Modern day bridge theorists have devised a use for this idle bid. This concept is the result of one of those developments, for which no individual bridge player has claimed proprietorship.

Note: It is of the utmost importance that the partnership not confuse a Major Suit Jump with a weak preemptive response on the two level. It is not possible for the responder to show a weak jump shift when employing this conventional method of showing a distinct Major suit distribution.

The concept of this conventional response method, without any interfering immediate bid by the next player in rotation, is to show a distribution of 5 Spades and 4 Hearts in both Major suits and an invitational holding.

Therefore, if partner opens 1 Diamond, then a first response by the responder shows a minimum of 5 Spades and 4 Hearts in both Major suits and an invitational holding. This means that the values do not extend to a game-forcing bid. Only if the opening partner holds additional values, then all further continuations will be forthcoming from the opening bidder.

The following example illustrates this concept:

North J109 QJ84 AQ76 K9

South AK643 K875 98 84

North		East		South		Meaning
1						Promises opening values.
		Pass		2		Promises a distributional pattern of 5 Spades and 4 Hearts. Values range from 9/10 to 12 points. This first response is purely invitational.
Continuations:
Pass						Shows minimum values and promises 3-card Spade support.
3						Shows game-invitational values and a 4-card Heart suit, and requests the responder to bid game with maximum or pass with minimum values.
3						Shows game-invitational values and at least a 3-card Spade suit, and requests the responder to bid game with maximum or pass with minimum values.
3 NT						Promises stopper(s) in the unbid suits. This rebid by the opener is risky with only minimum values. With additional values and no 8-card fit in either Major suit, then this rebid seems a likely and viable option.

Acceptable Over A 1 Club Opening Bid

There is no rational logic as to why this conventional method should not be employed following an opening bid of 1 Clubs. The same parameters of the concept would apply.

If you wish to include this feature, or any other feature, of the game of bridge in your partnership agreement, then please make certain that the concept is understood by both partners. Be aware whether or not the feature is alertable or not and whether an announcement should or must be made. Check with the governing body and/or the bridge district and/or the bridge unit prior to the game to establish the guidelines applied. Please include the particular feature on your convention card in order that your opponents are also aware of this feature during the bidding process, since this information must be made known to them according to the Laws of Duplicate Contract Bridge. We do not always include the procedure regarding Alerts and/or Announcements, since these regulations are changed and revised during time by the governing body. It is our intention only to present the information as concisely and as accurately as possible.