Roman Key Card Blackwood (RKCB)

Roman Key Card Blackwood (RKCB) has largely replaced the standard version among tournament players. It developed from the Roman Blackwood variant (see below). According to RKCB there are five equivalent key cards rather than four aces; the trump king is counted as one. The key card replies to 4NT are more compressed than standard ones and they also begin to locate the queen of trumps. 5 0 or 3 key cards 5 1 or 4 key cards 5 2 or 5 cards without the trump queen 5 2 or 5 key cards with the trump queen[1] Although the replies to 4NT are more compressed, it is almost always possible to infer which number of keycards is correct: 0 or 3, 1 or 4, 2 or 5. Evidence for that inference includes the entire auction as well as the number of key cards that the 4NT bidder holds. The 5 and 5 replies with 2 or 5 key cards also deny and show the trump queen, respectively. (Respondent may also show the queen with extra length in trumps, where the ace and king will probably draw all outstanding cards in the suit.) The 5 and 5 replies tell nothing about the queen or extra length, but the 4NT bidder may ask about that using the cheapest bid other than five of the trump suit. The code for replies to that "queen ask" vary; a common rule is that the cheapest bid in the trump suit denies the queen or extra length and any other call shows it. Roman Key Card Blackwood is predicated on existence of a trump suit, which determines which of the four kings and queens respondent should show as key cards. Trump agreement is not necessary, however. One common rule is that the last suit bid before 4NT bid is the key suit, lacking trump agreement. [edi ]1430 RKCB Some partnerships use the club response to show 1 or 4 and the diamond response to show 3 or none; this is referred to as "1430" while the original version is "0314". In order to facilitate the Queen asking, an experts' version has been developed, where "1430" is used by the strong hand and "0314" is used by the weak hand. There are specific rules which determine when the asker hand is the weak one and when it is the strong one.[2] [edit]Roman Blackwood A variation of the standard Blackwood convention, known as Roman Blackwood, was popularized by the famous Italian Blue Team in the 1960s. In Roman Blackwood, the responses are even more ambiguous, but more space-conserving. The basic outline of responses is: 5 0 or 3 aces 5 1 or 4 aces 5 2 aces In practice, the ambiguity is unlikely to occur, as a strength difference between hands with 0 or 1 and 3 or 4 aces is big enough that it can be established in previous rounds of bidding. In other words, a partner who has previously shown, for example, 12-15 range of high points is unlikely to hold 3 aces for his bid, etc. Even Roman Blackwood convention has several variations, revolving around 5 and 5 responses. In all variants, they denote 2 aces. One variation is that 5 shows extra values, while 5 does not. In other variations, responses 5 - 5NT denote specific combinations of aces (same color, same rank, or "mixed"). If the querying partner ascertains that all aces are present, he can continue as follows: 5NT is the Grand slam force The first available bid which is not the agreed suit is the Roman Blackwood for kings. The partner responds stepwise, as above.