User:Brian/Bridge/Subsequent bidding after an inverted minor raise
Inverted minors is a system in which a single raise of opener's minor is strong while a jump raise is weak. That is, 1♦ - 3♦ shows a weaker hand (on responder's part) than 1♦ - 2♦. This is the opposite of major suit raises, where a jump raise is stronger than a single raise.
The reason why many partnerships play minor raises inverted is that minor suit contracts are not actually the most desirable. Even with a minor suit fit, notrump is often preferable. By making the strong raise only a single raise, bidding space is conserved so the partnership can figure out whether or not to play in notrump. Specifically, a raise of the minor implies that no major suit fit can exist, so the minor suit and notrump are the only two options. With stoppers in all suits, a 3NT game is preferable to a 5m game, since making a 5m contract requires additional strength. Therefore, following an inverted minor raise, one partner or the other usually initiates stopper-bidding to determine whether notrump is viable.
Meanings of subsequent bids
If you are opener, you must alert your partner's raise.
After a double raise by responder, you should pass. Remember that a double raise can be made with a very weak hand. If you think 3NT is worth investigating now despite partner's potentially very weak hand, shouldn't you have opened 2♣ or 2NT originally instead of 1m?
|I have a minimum (12- HCP), and partner is a passed hand||Pass. Some partnerships have an agreement that the single raise is one-round forcing, but in this particular circumstance it really makes no sense to continue bidding—with a minimum hand opposite an invitational hand, 3NT is out of the picture, and rebidding 3m has no potential upside, not even preemptive value given that both opponents have passed.|
|I have a minimum (12- HCP), and partner is an unpassed hand||Rebid 3 of your minor. (Since 2NT has now been bypassed, any subsequent stopper-showing bid by partner indicates enough strength for 3NT.)|
|I have 13–14 HCP with stoppers in all side suits||Bid 2NT. Partner will sign off in either 3m or 3NT depending on strength.|
|I have 15+ HCP with stoppers in all side suits||Sign off in 3NT.|
|I have extra strength (15–18 total points) with a void or small singleton in a side suit and stoppers in the other two side suits||Make a splinter bid. Exception: avoid splintering in clubs since bidding 4♣ makes it impossible to sign off in 3NT.|
|I have a maximum (19+ total points)||TODO: how to do minor-suit slam bidding?|
|I have a side suit stopper but I don't have all three side suits stopped.||Initiate stopper-bidding as described below.|
|Otherwise (I don't have any side suit stoppers)||(TODO: Can responder make an inverted minor raise if they have all three side suit stoppers?)|
|Partner rebid 3NT after my raise||Pass.|
|Partner rebid 2NT after my raise and I have 12+ HCP||Raise to 3NT, since partner's 2NT rebid shows 13–14 HCP.|
|Partner rebid 2NT after my raise and I have 11- HCP||Sign off in 3m.|
|Partner bid a new suit after my double raise||See below on how to participate in stopper-bidding.|
|Partner jump-shifted after my single raise||This is a splinter bid; respond accordingly.|
|Partner bid a new suit after my single raise||See below on how to participate in stopper-bidding.|
|Partner rebid 3m and I have 14+ HCP with all the side suits stopped||Sign off in 3NT.|
|Partner rebid 3m and I have 14+ HCP with at least one side suit stopped||Initiate stopper-bidding (see below).|
|Partner rebid 3m and none of the above are true||Pass. (TODO: What if responder has slam interest?)|
In order to determine whether a notrump game is advisable, partners bid stoppers up the line. Once stopper-bidding has commenced, rebids by either partner are as follows:
|My partner returned to the agreed minor||Pass. Partner is telling you that the partnership is missing one or more side-suit stoppers so you do not belong in notrump.|
|My partner bid 2NT, but I know that we have enough strength for game.||Raise to 3NT, since partner's bid of 2NT means they believe all side suits are stopped.|
|My partner bid 2NT, but I don't have enough strength to force to game.||Sign off in 3 of the agreed minor.|
|My partner bid a side suit, bypassing a suit in which I also have no stopper. (For example, 1♣ - 2♣ - 2♥ denies a diamond stopper.)||Sign off in the agreed minor at the cheapest available level, since partner has just denied a stopper in the bypassed suit.|
|My partner bid a side suit and I now know that we have all suits stopped.||Sign off in 3NT if you know the partnership has enough strength; otherwise bid 2NT. Partner's subsequent raise to 3m or 3NT is to play.|
|My partner bid a side suit, I have game-forcing strength, and I don't yet know whether all suits are stopped.||Bid the cheapest available suit in which you have a stopper you haven't shown yet, letting partner you have that suit stopped.|
|My partner bid a side suit, I don't yet know whether all suits are stopped, and I also don't know whether we have enough strength for game.||Bid your cheapest available stopper if you can do so without bypassing 3m. If you cannot do so, then sign off in 3m.|