/Gerber. While it is true that the traditional Gerber sequence only crops up over a 1NT or 2NT opening and rebid, life is not that simple. There are a host of sequences in most players’ agreements where you might want to ask for aces with a call other than 4NT..…and equally there are sequences where 4NT is not Blackwood. Let’s deal with ace-asking bids other than 4NT first. Since few of us have such a call – and few of us would want to have such a call – below 3NT, let’s look at 4ace-asking.
1. After a pre-empt by your partner in any suit but clubs, what does a response of 4mean? Many people play 4as a modified form of Keycard. Responses are 4
no keycard, 4
one keycard, 4ª one plus the trump queen, 4NT two keycards, 5two plus the trump queen. After a 3opening 4is the ace-ask. Why would you want to have that call available? Well, if you play Key Card Responses as 14-30 or 03-14 keycard imagine you pick up: 
AKJ743 5 AK Q1084. Facing a 3pre-empt use Blackwood and get a 5response and you may not be happy! The 4ace-ask gets you out in comfort below your suit. Even facing a 3opening you might want to ask for aces with KQ10xxx Qxx AKJ A, just in case you find two keycards opposite; this way you can stop in 4facing xxx KJxxxxx Qx x, , when 5might go down on a ruff.
For those of you whose pre-empting style varies on the ‘hyper-aggressive’ side you may care to know that Karen McCallum’s responses to the 4ask includes an additional first step of 4meaning ‘Not only do I have no key-cards but I’m sorry you asked me that question, and you will be too’.
2. The second area where a Gerber equivalent makes sense is in response to a Stayman enquiry to 1NT finds a fit. Since 3/3are available as natural, three of the other major, 4and 4can take care of hands with a fit, allowing the 4NT response at the second turn to be quantitative. There are sensible variants possible to the following style, but for simplicity and ease of memory you can sensibly play that after e.g. 1NT–2– 2:
3Agrees hearts, promises shortage somewhere; 3NT relays for the shortage, with 4/4/4showing //shortage respectively.
4 Keycard Gerber for hearts
4 Balanced slam-try with four hearts
Higher suits would be Exclusion Blackwood (Blackwood ignoring the suit bid to ask)
4NT Quantitative with four spades
3. Just as in case 1 above, when a minor is set as trumps it may be convenient to ask with a cheaper call than 4NT, even after a regular opening bid. Minorwood – where four of the trump suit is the ask – or Redwood – where the ask is one over the trump suit – both make sense. I prefer the latter to allow me to raise the minor-suit without taking control. Sequences such as 1– 2 (inverted) – 4, OR 1– 2– 2Any – 4are ace asking agreeing clubs. 1– 1Any – 2or 3– 4, and 1– 2– 3– 4are also Keycard Blackwood. In almost all these latter sequences having a natural and quantitative 4NT available will come in handy sooner or later. More than likely you would have no partnership agreement as to what those bids may mean anyway.
4. 4NT as traditional ace-asking does not apply in the very early rounds of bidding whenever there is another sensible meaning for the call and you could set trump and then use 4NT. Accordingly an opening 4NT can be played as specific-ace-asking. As my partner at the Gold Coast last year demonstrated, an opening 4NT with e.g.: AKQ10876 — KQJ53 4 allows the partnership to play slam facing the club or diamond ace but not facing the heart ace (but do agree this with your partner before trying it!). Equally, facing a one-level opening bid, the best way to set trumps and then ask for aces is to use an inverted minor/Jacoby 2NT and follow up with 4NT. Meanwhile a 4NT response to the opening 1call might be just for aces, with a hand such as: x AKQJxxxx KQx x. A keycard response would include the spade king in the mix – NOT what responder wants to know about!
5. Exclusion Blackwood1 (Note below) is another area where partnerships tie themselves in knots. The simple rule should be that in almost any sequence where a player could use an unambiguous splinter-bid, a call one-level higher is Exclusion Blackwood. The most common Exclusion sequence is after a Texas Transfer2 (Note below) to hearts or spades following a 1NT or 2NT opening call. Now 4NT is keycard (letting 1NT–2–2and 1NT–2–2– 4NT should be quantitative) and new suits are Exclusion Blackwood. Equally after 1–2jumps are splinters by either hand, double jumps are Exclusion Blackwood. Also in a Jacoby auction 1– 2NT – a five level bid is Exclusion Blackwood by either player. If one hand is limited, though, the double jump should probably just be void-showing with a single jump being splinter.
Please, please, agree with your partner if an auction such as 1–1–1–5 is Exclusion or to play, before having to guess at the table how he is torturing you.
6. 4NT should not be Blackwood until a suit is explicitly agreed. While a sequence such as 1–2–3–4NT might be construed as Keycard Blackwood for clubs I’d always bid 4over 3 and then use Keycard Blackwood. More clearly, 1–2–3–3–4NT or any jump to 4NT after a fourth-suit enquiry just shows more than a 3NT bid would show. When the opponents pre-empt at the three – level opener will frequently have to decide if e.g.: 1–[3]–Double or 3–[Pass]–4NT is quantitative with 18-19 or Blackwood. My view is that one should if possible cue-bid, then ask for aces, thus letting the direct jump be natural and quantitative.
7. If you play strong jump shifts, then you need to agree what suit is trumps in auctions where responder jumps then bids 4NT. The simplest rule is that responder’s suit is always trumps if he uses 4NT at his second turn. In other words although these two auctions: 1–3–3NT–4NT, and 1–2–3–4NT sound as if they are quantitative and agreeing hearts respectively, in fact both auctions agree responder’s suit unilaterally.
8. Non-jump 4NT bids in competition are only keycard if you have another way to show unbid suits, or have been left enough space for it to be unambiguous that 4NT is not take-out. Contrast 1:[4]: 4NT (Blackwood) and 1-[4]-4NT for minors or red-suits. Equally it looks best on an auction of this sort: 1– [1]–2–[4]–4NT as takeout oriented to the minors not keycard for clubs. Opener rates to have e.g. x Axx KJxxxx KQx.
Notes
1 Exclusion Blackwood applies when one hand specifically shows a void in the bid suit, and asks for keycards excluding the ace in the bid suit.
2 1NT-4/4are transfers to hearts and spades respectively. These show six-card suits either with no slam interest, intending to pass the transfer, or about to use Keycard Blackwood, or with a side void.
