1NT 'Multi' Overcall

   

In this text the term 'ANCHOR' suit refers to the lowest unbid suit.

The term '2nd suit' refers to the next highest unbid suit above the anchor suit.

The term 'portion' means at least a 3+ card holding in the 2nd suit

Our 1NT overcall is 'unusual' and strictly alertable

a) It can be used in either position, that is as a direct overcall or in the protective position, following either opponent's opening bid of 1 in a suit. [If a minor suit is alerted this has no effect on our 1NT overcall - treating it as a natural  opening even if a strong club opening or a Precision 1D ]
[We prefer the use of TRAP to defend strong artificial 1
openings 16+HCP,  where the 1NT overcall shows either D+S or C+H 4-4 or better , and there is another defence for a precision 1 opening too]

b) It is artificial & alertable. It can be weak or strong (15+ HCP), single suited OR 2-suited in the lowest 2 unbid suits OR even 3-suited OR some strong hands - of these options the most frequent is the 2-suited usually 5-5 in the lowest 2 suits. If partner holds the ANCHOR suit (the lowest unbid minor) it will offer some comfort!
Nevertheless Partner is required to respond with 2 unless the INT overcall has itself been either overcalled or doubled (see below)
c) Its exact nature is only known when the 1NT overcaller rebids.
d) One suit, known as the 'ANCHOR' suit is always known - this is the lowest unbid minor which must be 4+ cards in length. E.g 1(opp)-1NT...  will contain 4+ Clubs and if the opponent had opened 1 then at least 4+ Diamonds will be held.
e) The 1NT overcall is to be considered initially as a pre-emptive bid to block opponents from making a simple 1-level response - this disruption of their bidding has often proved valuable. Subsequently when the nature of the 1NT overcall is exposed partner can make a further decision to possibly compete effectively with the opposition.
f) If opponents minor suit opening is alerted as possibly 0-2 cards then Holding a good 5+ card suit in that minor: we may should make a direct overcall in their suit ONLY when holding opening values and a single-suited hand and the opponents inform that their alerted minor can be 0-2 cards.
This approach also has a useful semi-pre-emptive effect on the opponents similar to a 1NT overcall. Partner must realise the significance of the alert and not take the bid as a cue-bid for the Majors.
This 2 or 1N overcall are more effective than overcalling in a Major which mostly tends to help opponents in their bidding!

Responder's options

Responder must bid 2 if his RHO passes. This is just a relay. (it carries no information except for denying a 6+ card Major)
A rare response maybe in an unbid Major: 2Ma - a weak 2:
If RHO intervenes responder bids (summary of above)

Types of hand declared with a 1NT overcall  are:

The anchor suit, always 4+ cards, is ALWAYS declared by the 1NT overcall: It is the lowest unbid suit. If opponents open 1, whether alerted or not, the anchor suit is Diamonds and 4+ cards are promised. Over any other 1-level opening the Anchor suit is always Clubs.

If interference: Summary of above)
PASS Usual
2C (over *) Shows support for anchor suit
** (over *) Shows  support for anchor suit and a portion in the 2nd lowest unbid suit
* (over 2any) Shows "                   "                    "               "              "            "               "

1. Weak uses & their rebids:
Partner will always assume a possible weak two suiter 5-5 in the anchor and 2nd suit.
(i) A minor pre-empt in the Anchor suit  6+ cards - shown by a rebid of 2 in the anchor suit OR pass if partner relayed with the anchor suit. Warning do not directly raise to 3-level - this shows a genuine 3-suited hand -see below
(ii) A minor pre-empt in Diamonds can be available IF AND ONLY IF diamonds is the 2nd suit (this can only be the case when opponents open in a major). This is shown only by a bid of 2D if available -
i.e. 1-2-6-4 distribution. If 2 bid is unavailable(e.g.opponent called 2H)  partner will assume you possibly have a weak 2-suiter in anchor+2nd suit.
(iii) A weak 2-suiter, 5-5, in the lowest 2 'unbid' suits - shown by a rebid of
2 Hearts if available. If Hearts is one of the 2 indicated suits then it may be passed, otherwise responder is to show preference unless opponents intervene. E.g. 1S-1N-*-**-2H-*-2S-
An interesting illustrative sequence: Partners ** showed Club support, NT bidders * of 2H says he would have bid 2H: this confirms a minor 2-suited hand at least 5-5. The rebid of 2H indeed turns the 1NT opening into what many players announce with a 2N o'call. This indeed is the most frequent use of the 1NT  overcall and sequences need not be as complicated as the one given above.

2. Strong 2-suited hands & their rebids:
(iv)  A strong 2-suiter, 4-5 LTC & 5-5 or better, in the lowest 2 'unbid' suits - shown with a rebid of 2 NoTrumps. Responder selects the better fit. If strong enough for game cue bids in another suit. Note this sequence, along with (iii) is equivalent to the  usual standard of a 2NT jump overcall.
(v) Shows 4+ cards in the Anchor suit & 6+ cards in any other 'unbid' suit - shown with a rebid of 3 in an unbid suit - there are 3 candidated! (not the anchor suit )

3. Strong 3-suited  powerful 6-4 hands and the rebids that display them:
A 3-suited hand is shown in 3 possible ways: Some may be blocked by opponents interference:  If the opponent actually makes your intended rebid a double signifies that you had intended it. A PASS indicates that your intended bid was lower than the opponents interference - partner can usually deduce correctly.
(vi) 3Anchor suit (usually Clubs unless opponents opened 1 in which case it will be Diamonds. Also if opponents opened in a minor then the 2nd suit is Hearts otherwise its the unbid minor): 3 specifiic suits are shown: EXCLUDES the 2nd suit. 15+ HCP, 4441 or 5440 also we allow 5431 if the 3 card suit is the opponents suit : Hhx where H=AKQ & h=JT9 with HCP count >=3.  Ex1:  1S-1N-P-2-P-3 shows ++. If the opening was 1 then your suits also ++. Partner may pass the 3 bid to play, bid 3S or 4S to play there,with a good guard in Opps suit bid 2N¦3N. Bidding the shortage is showing long suit length.
(vii) 2S: 15+ HCP;
This bid retains its previous meaning showing all suits excluding opponents opening suit. Partner can PASS  showing Spade support in a weak hand, show 4+ card support for any of the indicated suits at the 3-level, bid 2¦3N to play with a great quard in the opponents suit & near game/game values.  Ex: 1 - 1N - P - 2 - P - 2 - 4  Partner bids game in Hearts. . Partner may now have  2N¦3N Naturally  showing healthy cover in the opponents suit and sufficiebt values.

Ex1: 1
-1N!-2-*!(shows Club suit & partial in Hearts)-P-3!-P-3N(no D guard,balanced hand)-P-5 or PASS with a good Diamond guard.
Ex2: 1
-1N!-P-2H(6+ card suit)-3(game force)-3N-P-4 or PASS (to play 3N) or 4N(RKCB - Hearts agreed)
Ex3: 1
-1N!-2-P(denies Clubs)-3-*(my bid! - game force)-P-3S(natural)-P-4N(RKCB-spades agreed) OR 3N...
4. Game going hands. 3-level  rebid in opponents opening suit. Partner with half a guard and no 6+ card suit bid 3N. Otherwise bids a 6+ card suit otherwiseNEXT suit.
The 3-level cue-bid: is also a changed bid - previously a 3-suiter, now essentially a game going hand that would normally be opened with 2,  Ex: 1-1N-2-3.
Partner is  invited to bid:
3N with half a guard.
Any 6+ card suit at 3¦4-level
Or 'Next suit' at 3-level asks overcaller to decide

4N(even no KC)  or 5-level bid(odd no KCthe bid pinpoints the lowest one held) are all TURBO


Notes:
(A) These bids are NOT as previosly designed. The original meaning of 3Anchor suit - a strong  hand in  that suit has been dropped to provide this most useful bid for 3-suited hands excluding '2nd suit'.
(B) 2S has the same specification as before: 3-suited missing opponets suit.

(C) The 3-level cue-bid of openers suit used to be a strong 3 suited hand in the other 3 suits. This has never happened in real life! so now dedicated to a hand that fully justifies a game force! i.e a solid 2C opening. It is still preferencial to use specialised bids if available :-
    E.g.: 3/ strong 2-suited jump overcalls
    E.g.: Double FORCING  where you would have intention to bid double a second time (also strictly Forcing). This approach is best when holding 2 good suits

This fills a hole in most systems where with a light opening can precede your partner holding a game going hand and the subsequent problems to declare the hand. Admittedly the resolution bgins at a highish level (this can happen to you in other ways like high 4/5 level pre-empts in today's game) but something is known in this case:- 4+ card Club suit & loser count in opps suit is max 1. We changed the usage of 3cue-bid as it very rarely happened - hence we have expanded its scope significantly.

Opponents bid 1 minor alerted

Our usual approach is to play a INT overcall as above when the opponents make an alertable minor suit opening effectively ignoring the possibility of the bid being a short suit. Now bidding 1NT denies a 5+ card suit in the opener's minor - and promises 4+ in the other minor now the Anchor suit.
So with 1!(opp): Clubs is our anchor suit and with 1!: Diamonds is our anchor suit. In both these cases Hearts is the 2nd suit.
We can take this approach effectively as:- we may make a natural 'cue-bid' over an  artificial minor opening showing opening values and a 5+ card suit at our first opportunity in  the bidding. E.g. 1C!-2C shows 5+ cards in Clubs and near opening values. This does not  show both Majors!
By  ignoring minor suit alerted bids, it also makes a 1NT overcall easier to master. Additionally, it provides for a very effective mild pre-empt over an alerted minor opening. An alerted 1! or 1! in precision openings are aimed initially at finding a 4 card Major fit and  or cue-bid effectively stop this from taking place at the 1-level and loses a round of bidding from the opponents.

The following is an alternative approach - (not in use).

Modified Roman style defence alternative to alerted minor suit openings

There is an  Optional experimental approach strictly only to be used by agreement.
It is designed to be used primarily over precision  1! or alerted 1 openings in conjunction with TRAP over strong 16+ 1 openings.

The concept involved is one of treating an 'unusual' bid with an 'unusual' response! Put another way: 'not guiding the opponents' and nevertheless showing a willingness to compete.
See Mathematical concept of the 'unusual'  for details - where Hearts become the required Anchor suit!
Reminder: Played optionally & only by agreement.

When opponents intervene before your rebid

All rebids that remain are possible. They always retain their conventional meanings.
If by chance opponents intervention matches your intended conventional reply a Double signifies this.
If you are robbed of your rebid you MUST PASS. However partner may well be able to deduce your probable intention and possibly bid appropriately!
Essentially nothing changes bidding follows its conventional bids. Even if your intended reply is exceeded by the opponents Most opponent  interventions will be at the 2-level and note well that all your rebids of 2 and above are stronger bids and opponents will interfere with great risk to themselves.

In many conventional situations conventional bids are replaced by natural bids following intervention. In the case of the multi NT this is not the case. We may also add it is also not the case in Beta's 2 sequences' or  4NT ERKCB where  step responses are replaced by a specific schema employing the additional bids of PASS and Double¦redouble as the first 2 steps.