Although the origin is unknown, the general consensus is that this conventional method was developed in England. It is sometimes referred to as the Kaplan Interchange, although it has little to do with the basic and fundamental Kaplan-Sheinwold bidding system. The problem arose owing to a particular problem presented mostly in the Two Over One system (approach) as developed by Mr. Max Hardy.
Note: Online sources indicate that the concept has a second designation called Gazille. This cannot be determined. Other sources indicate strongly that the concept may have devised by Mr. Edgar Kaplan.
Note: The designation, or more accurately the name of Gazille is from an online game. His picture is presented below. The creation is one of many from the online community of artists and art lovers.
Principles of the Concept
The following illustrations should clarify the problem.
| West |
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East |
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1  |
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1 NT |
In the Two Over One system (approach), after West opens the auction with 1 Heart, the responder, with no Heart support is obliged to respond 1 No Trump, which is one round forcing and shows that the initial values are insufficient for game. In the above example, the opener then, holding 16 plus high card points, has the opportunity to make a reverse bid by rebidding 2 Spades, showing a 5-card Heart suit and a 4-card Spade suit.
The above illustration is rather text book and is straight-forward. The bidding problem arises when the opener has the following holding, whereby a reverse bid is not available.
| West |
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East |
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| 1 |
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1 NT |
After an opening of 1 Heart, the responder is again forced to bid 1 No Trump, which is one round forcing and indicates that no game-forcing values are present. However, the opener may not make a reverse bid, while the high card points are insufficient. The opener is forced to rebid the better of the Minor suits.
The problem with this manner of bidding is that the responder may not show a 4-card or even a 5-card Major suit with the first response, since the object is to first show the presence or absence of game values. In order to create a forcing action and to show either a 4-card Spade suit, or even a 5-card Major suit, the auction and the terms of the partnership agreement have been altered. The term describing this conventional method is named Granville, and by some the Kaplan Interchange. The following illustrations should clarify this concept of bidding.
| West |
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East |
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| 1 |
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1 NT |
By first responding 1 No Trump, the responder, according to the partnership agreement, shows at least a 5-card Spade suit. This first response is forcing for one round. The ensuing auction then becomes standard.
| West |
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Meaning |
2  |
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Shows a 4-card Club suit. |
2  |
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Shows a 4-card Diamond suit. |
| 2 |
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Shows a 6-card Heart suit and a 2-card Spade suit or less. |
2  |
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Shows at least a 3-card Spade suit and 12+ to 15- points. |
The rebids of the opener, in this case West, are conventional, as are all ensuing rebids.
If this method becomes the conventional manner for the responder to show a 5-card Spade suit, then the necessity arises for the responder to show a 1 No Trump one round forcing bid. The following illustration should clarify this bidding alteration:
| West |
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East |
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| 1 |
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1 |
| 1 NT |
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In the case that the responder does not have a 5-card Spade suit, then the bid of 1 replaces the normal 1 No Trump forcing first response in the Two Over One bidding system. This first response forces for one round and strongly promises a possible maximum of 4 cards in the Spade suit. The above mentioned continuations remain valid and the auction continues as had the responder first responded 1 No Trump. The one exception is shown above in the illustration. If the opener indeed has a 4-card Spade suit, then the opener will first rebid 1 No Trump, showing a 4-card Spade suit and 12+ to 15- points.
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.