OPENER'S REBID AFTER 2D-2H (TRANSFER TO NO-TRUMPS)
* 2D 2H IS NOT THE DEFAULT RELAY. Most hands should not be replying 2H to 2D and it's a mistake to do so simply on the grounds that it's a cheap bid and tells you more about opener's hand. It's unsuitable for most circumstances and probably won't let you stop in 3NT.
* HAND TYPES THAT CAN BID THE 2H RELAY: (a) weak hands that are intending to stop in part-score in no-trumps or spades, (b) hands of any strength that want to show spades, (c) a game-going hand with 5-4 in the majors, (d) a more vaguely defined class of hands that are thinking of playing a high-level contract in a minor, although might not end up doing so.
* DO NOT RELY ON THIS SUMMARY. It's an approximate guideline of what comes next, not a road map. Responder's continuations after opener's rebid (below) are complex and there are exceptions to what I'm about to say here. This block of text isn't trying to prescribe rules in detail, but merely attempting to give an idea of the overall flavour in what might have seemed a bewildering array of options. There will certainly be specific sequences for which the following is incorrect.
* AFTER TWO-LEVEL RESPONSES, there's a Stayman-like 3C bid showing at least 5-4 in the majors, a flexible transfer that allows under/super-accepts (3D) and a strict transfer (3H) to spades that doesn't give opener the option.
* FOUR-LEVEL REBIDS FROM RESPONDER can have various meanings, but generally promise a spade suit, which is one of the main purposes of the 2D 2H relay sequence.
* HIGHER REBIDS FROM RESPONDER follow the usual rules for Exclusion Blackwood, Complete Two-Suiters and so on, promising a spade suit.
|Pass after double||Shows a non-horrible four-card suit, willing to play in the doubled conventional bid if partner has trumps too.|
|Redouble||To play, good five-card suit, but partner's allowed to take it out if unsuitable.|
|2S||any five-card suit, mustn't be horrible|
|2NT||denying a five-card suit (but might be suppressing a horrible one)|
|3C, 3D, 3H||natural, 4-card suit in a 5422 hand with five spades|