Roman Key Card Blackwood 1430
With no agreed suit nor self-sufficient suit bid, standard Blackwood is used
although some people play that the last bid is the key suit. Clarify this with partner.
The ACBL says:
Common ace-asking bids and expected responses thereto, such as Blackwood
(4NT) and Gerber (4)... do not require an Alert during the auction.
ACBL's theory for not alerting during the auction is that an alert is more likely to "wake up partner" than to help the opponents.
You would think that "common ace-asking bids" would not include bids like Kickback, Exclusion, 6-Ace, and Last Train. And in fact elements of 1430 are not known to all club players, such as void-showing and even queen asking.
However, in another place, ACBL says that ALL bids over 3NT, starting with opener's 2nd call, are exempt from alerting during the auction. So 1-(P)-4 (Minorwood) must be alerted immediately but 1-(P)-2-(P)-4 (also Minorwood) may not alerted during the auction because the ace-asking started with opener's 2nd call.
Either way, the non-common bids are supposed to be alerted AFTER the auction and before play. This is nice, but too late if you would have made, say, a lead-directing double. Your only recourse is to ask for an explanation if any kind of unusual looking bid over 3NT is made.
However, a good general principle is to NOT ask for an explanation of any bid until the bidding is over unless you intend to make a bid because by asking, you are giving the opponent a chance to explain his bid to partner in case they were not on the same wavelength. Supposedly, the explanation would be unauthorized information to partner, but the use of such information would be almost impossible to detect much less to enforce.
When NOT to Use Ace-Asking:
It is normally considered a mistake to ask for aces/keys when holding a void or a worthless 2+ cards.
Say that you have 2 aces and a worthless doubleton. If you bid 4N and partner shows 1 ace, you don't know if his ace is in the suit of your doubleton or not.
Likewise, if you have a void, an ace and two king-high suits and partner shows 1 ace, then if his ace is in your void, you have 2 losers off the top whereas if his ace is in one of your king-high suits, you only have 1 quick loser.
So if partner bids 4N, he is assumed to have one of the following in each suit: A, Kx, or x -- no voids, no worthless doubletons. When you tell him your number of aces, he knows for sure how many suits he has covered.
In 1430, if you don't have the trump K and are also missing two aces, then if partner doesn't shows 2 key cards, you can't bid slam.
You also cannot ask for aces if a response would force you to slam.
For example, if hearts are the agreed upon trump suit and you are missing 2 keys and partner responds 5D, showing 0 key cards, you can still sign off in 5H. But if clubs are to be trumps, you would be forced to bid 6C over 5D.
Mike Lawrence's column in the August 2020 ACBL Bridge Bulletin, page 48, contains an excellent discussion of another circumstance when a player should not use Blackwood - it is when he has all the aces, because asking for aces when you have them all is pointless.
Even with a hand like AQ83-AJ743-AK7-4, it is the player with Kings and Queens who can better use the information about aces.
With the above hand, Lawrence says North shouldn't bid 4N at any point in this auction because he has lot of holes that need to be filled (while South primarily needs to know how many aces North has). In this case, a cue-bidding sequence was used instead.
This deal from the 2019 European Youth Teams tournament is a very fine example of slam bidding combining a number of techniques.
After South completes the transfer to spades (an unusual agreement), North control bids his A to show slam interest. South cooperates by control bidding diamonds. This could show either an Ace or King, but since North has the King, he knows that South is showing the Ace.
The reason North didn't start by bidding 4N is that if South just showed 1 Ace, North wouldn't know if it was the diamond or heart ace, and if it was the diamond, North could be off two quick heart tricks. But now North can bid 4N because South is either going to show 1, which is known to be the diamond, or 2, in which case all key cards are accounted for.
South's 5 response shows 2 key cards (Aces in this case) plus the Queen of trump. Some Norths may now bid 6 of the trump suit in situations like this as a sign-off, but that denies holding all the controls since it doesn't cost anything to bid 5N first. So North bids 5N to confirm all keys and to ask for Kings.
Some people agree to show the lowest King and others show the number of Kings outside of trumps. South's 4 is the former. North reverts to control bidding to show the K.
South's 6 response might normally show the K, but South might have figured that having the KQ more than made made up for the missing K and was the only bid he could make without going over 6.
Another possible explanation for the 6 bid is that South would expect North to understand that with the K South would have bid 7, so bidding 6 instead denies the K and shows 3rd round control in case North had Kxx... instead of Qxx..., but that's pretty sophisticated for us club players. Whatever the meaning, North thought it was enough for him to bid 7.
Asking for Aces Only:
Say that you have a running trump suit and partner opens 1 of a suit. All you need to know is how many aces he has. An immediate jump to 4N asks for aces only. (See Feb.2020 Bridge Bulletin page 51.)
4NT Responses can show the number of key cards (Aces + trump King), trump Queen, void.
5 = 1 or 4 keys counting the trump King
5 = 0 or 3 keys counting the trump King
Asking for the Trump Queen:
5 = 2 or 5 keys WITHOUT the trump Queen
If responder bids 5 or 5, he is not able to show the trump Queen.
Asker may bid the next higher non-trump suit to ask about the Queen:
After 4N-P-5-P. Asker bids 5 if Diamonds are not trumps; otherwise, he bids 5.
After 4N-P-5-P. Asker bids 5 if Hearts are not trumps; otherwise, he bids 5.
Bid the trump suit without the trump Queen.
Bid 5N with the trump Queen and no side-suit Kings.
Bid a non-trump suit with the trump Queen AND the King of the suit bid.
5 = 2 or 5 keys AND the trump Queen
5N = 0, 2, or 4 keys with an unnamed void
6// = 1 or 3 keys and a void in the suit bid excluding the trump suit.
For example, if Diamonds are trumps and bidding has gone 4N-P and you have a void in Hearts,
bidding 6 lets your partner know that you have a void in Hearts or Spades without going past 6.
(If the void were in Clubs, you would have bid 6.)
If Hearts are trumps, you can bid 6 or 6 to show 1 or 3 keys and a void in the suit bid.
Since you will not bid 6 if Hearts are trumps, a bid of 6 indicates 1 or 3 keys and a
void in Spades, the only suit left, without your having to bid past 6.
5N Asks for number of Kings, excluding the trump King, and implies having all keys.
6 = no Kings
6 = 1 King
6 = 2 Kings
6S = 3 Kings
RKCB In Competition
Jump to 4 of the suit above the agreed trump suit for RKCB 1430 excluding the suit just bid.
Click the link above for details.
6-Ace Roman Keycard Blackwood
RKCB - Kickback (Includes Redwood which is just for the minors.)
If the club suit is agreed and 4N is used and responder must bid 5 with no keys, then you are already past 5. By using Kickback, this is not a problem.
Instead of 4N, asker bids the next suit over the last bid one and responder continues RCKB 1430 up the line.
1 - 1, 3 - 4 ...
4 = asking
1 - 1, 3 ...
4 = 1 or 4 keys
4 = 0 or 3 keys
4N = 2 or 5 without Queen
5 = 2 or 5 with trump Queen
5 = 0, 2, or 4 keys with an unnamed void
5/5/6 = 1 or 3 keys and a void in the suit bid
excluding the trump suit.
3 = asking
3N = 1 or 4 keys
4 = 0 or 3 keys,
Trump Queen Ask:
The first two responses to Kickback, as with regular RCKB, provide no information about the trump queen. To ask if responder has the Queen, asker bids 1 suit/NT higher than responder's last bid, bypassing the trump suit if necessary.
If responder does not have the Queen, he bids 1 suit higher than the asker. Two steps higher shows the Queen.
Last Train Cuebid
Minorwood solves the problem of regular RCKB taking you past the level for game in the minors. By bidding the agreed upon minor on the 4 level, such as 1 - 3 - 4. Note that 4 after 1-3N is Minorwood, not Gerber.
Responses can be the same as your favorite version of Blackwood.
A variation of Minorwood involves skipping a step in the replies. For example, in regular Minorwood,
after 1 - 2 - 3 - 4, responder's bids would start with 4 but using this variation, his bids would start at 4.
This leaves the skipped suit for reversing the replies. So after a 4 ask, the 4 reply turns the tables and asks partner to show HIS aces/keys. Again, if responder to 4 doesn't want to do the reverse, he just skips hearts and spades begins his reply levels.
If the trump suit is Clubs and asker bid 4, then diamonds becomes the reversing suit and otherwise, responder's replies start with hearts.
See the March 2020 Bridge Bulletin, page 37, #1.
E: AKJ3 T8 AK875 AJ
Bidding: 2N-3, 3-4, 4-4N, Pass
W: Q9 K765 9 KQ8643
3 is Modified Stayman with 3 denying 4 hearts or five spades. 4 is Optional RKCB, a newer technique that many pairs are now using. It shows clubs and implies exactly 4 hearts and gives opener the topion to answer key cards if interested in slam. This effectively allows a quantitative move by responder with the ability to check on key cards at the same time.