Opposing 1NT
Wbridge5 defends against a 1NT opening with Landy 2♣ and
Multi-Landy 2♦, 2♥ and 2♠. Both are optional conventions in the
program. Both are on by default (Nslandy and NsMulti_landy in
WBRIDGE5.INI), and this chapter reports that default. The double is for
penalty.
The probes dealt the opponents’ 1NT from Wbridge5’s own system, a 15–17 HCP 1NT, at no vulnerability. The SEF and SAYC presets for the opponents leave that range unchanged. Ranges here are in HCP, as the probes give them.
Three principles run through the defense.
- Pass is the default. There are no natural 2♣ or 2♦ overcalls, and a long minor is rarely shown below the 3 level.
- Every 2-level overcall shows a major. The minors wait for 2NT or a 3-level preempt.
- Strong hands double. From about 15 HCP a double replaces every shape-showing call except Landy and 2NT.
Direct seat
| (1NT) | |
|---|---|
| X | PEN, 15+ HCP, any shape |
| 2♣! | Landy, 5+♥ 4+♠ or 4+♥ 5+♠, 9+ HCP; or 4=♥ 4=♠, 13+ HCP |
| 2♦! | Multi, 6+♥ or 6+♠, 7–15 HCP |
| 2♥! | 5=♥, 4+ in a minor, 9+ HCP |
| 2♠! | 5=♠, 4+ in a minor, 9+ HCP |
| 2NT! | UNT, 5+♦, 5+♣, 7+ HCP |
| 3♣♦ | PRE, 7+#, 7–13 HCP |
| 3♥♠ | PRE, 7+#, 7–12 HCP |
Double
The double is a penalty double. Balanced hands double from 15 HCP: 16 of 23 hands with exactly 15 HCP doubled, and every balanced 17+ HCP hand did unless it held both majors. Shapely hands join at about the same strength. A 6-card major doubles from 16 HCP rather than bid 2♦, and so does a 5-card major with 4 cards in a minor.
- ♠AK3 ♥K6 ♦J652 ♣AK53: X.
- ♠76 ♥A109 ♦AKQ962 ♣A7: X.
- ♠A3 ♥AK9732 ♦A ♣J1092: X, not 2♦.
- ♠AK2 ♥Q3 ♦Q7532 ♣KJ6: Pass, 15 HCP.
A 5-3-3-2 hand with a 5-card major has no Multi-Landy call, so it passes or doubles. It passes up to about 16 HCP and doubles from 17.
- ♠AQ987 ♥109 ♦AJ6 ♣AJ9: Pass, 16 HCP.
Landy 2♣
Landy shows both majors. A 5-4 or longer hand bids 2♣ from about 9 HCP. At 8–9 HCP Wbridge5 bids it on about 4 boards in 10. A 5-5 hand bids from about 6 HCP. With 4-4 in the majors, Landy needs 13 HCP and stays the call up to 18 HCP instead of a double. A 6-4 hand usually bids 2♣ too, and 2♦ only now and then.
- ♠AJ765 ♥A10984 ♦5 ♣75: 2♣.
- ♠Q642 ♥A9632 ♦5 ♣K83: 2♣.
- ♠A954 ♥A764 ♦Q86 ♣K4: 2♣, 4-4.
- ♠A9652 ♥7643 ♦A9 ♣109: Pass, 8 HCP.
Multi 2♦
2♦ shows one long major, at 7–15 HCP. At 6–7 HCP the call is mixed. A 7-card major chooses between 2♦ and a 3-level preempt, with no clear rule in the data. A natural 2♠ shows up on only 3 of 300 boards, all with 7 spades.
- ♠AJ10865 ♥K107 ♦6 ♣643: 2♦.
- ♠AQ10765 ♥105 ♦J2 ♣1097: 2♦, 7 HCP.
- ♠KJ10873 ♥103 ♦J5 ♣Q84: Pass, 7 HCP.
- ♠KJ105432 ♥7 ♦KQ2 ♣106: 3♠.
Multi-Landy 2♥ and 2♠
2♥ and 2♠ show 5 cards in the bid major and 4+ cards in an unspecified minor. Hands with 4+ in a minor bid it from about 9 HCP and always from 10. With no 4-card minor, the major alone is not enough.
- ♠8 ♥AJ973 ♦K1065 ♣J63: 2♥.
- ♠KQ1084 ♥105 ♦KQ83 ♣96: 2♠.
- ♠QJ985 ♥A4 ♦K108 ♣KJ4: Pass, 14 HCP.
Minors
The minors have no 2-level overcall. 2NT shows 5-5 or longer from about 7 HCP and keeps that meaning up to 16 HCP. A 5- or 6-card minor without the other minor passes until it is strong enough to double. A 3-level overcall is a preempt, mostly with 7+ cards. Only 2 of about 60 hands with 6 clubs and 8–13 HCP bid 3♣.
- ♠9 ♥82 ♦A10764 ♣A10752: 2NT.
- ♠KJ6 ♥J3 ♦Q ♣AQ107542: 3♣.
- ♠982 ♥7 ♦AKJ10853 ♣72: 3♦.
- ♠Q4 ♥K10 ♦A85 ♣KQJ732: Pass, 15 HCP.
- ♠3 ♥A43 ♦KQ86 ♣AQ1098: X.
Over a weak 1NT
The probes also told Wbridge5 that the opponents play a 12–14 1NT
(EO1Sa=12, EO1SaNV=12). The structure did not change. The double
still starts at about 15 HCP. Balanced 13–14 HCP hands doubled only 6
times in 71, compared with none in 71 against 15–17.
Balancing seat
In the balancing seat, Wbridge5 plays the same Multi-Landy as in the direct seat. The double needs 17 HCP. Balanced and semi-balanced hands with 15–16 HCP pass. The other calls show the same shapes at about the same strength.
| (1NT) P (P) | |
|---|---|
| X | PEN, 17+ HCP |
| 2♣! | Landy, 5-4+ majors, or 4=♥ 4=♠ with 13+ HCP |
| 2♦! | Multi, 6+♥ or 6+♠ |
| 2♥! | 5=♥, 4+ in a minor |
| 2♠! | 5=♠, 4+ in a minor |
- ♠AK8 ♥K1073 ♦KQ932 ♣9: Pass here, but X in the direct seat.
- ♠AJ98 ♥A5 ♦K65 ♣A764: Pass, 16 HCP.
- ♠AK92 ♥K87 ♦K84 ♣AJ6: X, 18 HCP.
- ♠Q10964 ♥AQ10 ♦6 ♣10743: 2♠, 8 HCP.
Without 4 hearts, a 4-card spade suit passes at any strength below the double. So does a 4-card heart suit with a 5-card minor.
Advances
After the double
| (1NT) X (P) | |
|---|---|
| P | Default |
| 2x | S/O, 5+#, 0–6 HCP, now and then |
Advancer passes on 291 of 300 boards, 0–14 HCP. It removes the double only sometimes, with a weak hand and a 5+ suit.
- ♠7 ♥QJ964 ♦982 ♣8543: 2♥.
- ♠J53 ♥7 ♦Q8632 ♣9652: Pass.
After the balancing double, (1NT) P (P) X (P), advancer passed on 164 of 165 boards. The one exception was a 3-HCP hand with 7 spades, which bid 2♠.
After Landy 2♣
| (1NT) 2♣ (P) | |
|---|---|
| P | 6+♣, 0–2 in each major, weak |
| 2♦! | Equal length in the majors (rarely 1–2 apart), any strength |
| 2♥ 2♠ | S/O, the longer major, 0–10 HCP |
| 2NT! | 14–16 HCP, game interest |
| 3♥ 3♠ | INV, 4+#, 6–12 HCP |
| 4♥ 4♠ | S/O, 4+#, 8+ HCP |
2♦ asks partner for the longer major. Advancer bids it with every equal-length holding from 1-1 to 4-4, at any strength up to 16 HCP. On 10 of 52 boards the majors differed by 1 or 2 cards.
- ♠AQ97 ♥A763 ♦1093 ♣94: 2♦, 4-4.
- ♠KQ4 ♥842 ♦1093 ♣AJ72: 2♦, 3-3.
- ♠10853 ♥987 ♦82 ♣J753: 2♠.
- ♠8732 ♥96 ♦K85 ♣KQJ7: 3♠.
- ♠AK8 ♥K1073 ♦KQ932 ♣9: 4♥.
- ♠Q2 ♥54 ♦86 ♣KQ109873: Pass.
After Multi 2♦
| (1NT) 2♦ (P) | |
|---|---|
| P | 6+♦, 0–3 in each major, weak |
| 2♥ | P/C, any strength |
| 3♥ | P/C, INV, 3+♥, 3+♠, 6–11 HCP |
| 4♥ | P/C, 3+♥, 3+♠, 8+ HCP |
Every raise is pass-or-correct: advancer does not know the major, so it holds 3+ cards in both. 2♥ is the usual answer, 191 of 300 boards, up to 16 HCP. The data has no 2NT ask.
- ♠Q3 ♥Q982 ♦A10983 ♣74: 2♥.
- ♠10876 ♥AJ3 ♦Q1094 ♣Q5: 3♥.
- ♠AKQ10 ♥972 ♦Q2 ♣K1087: 4♥.
- ♠86 ♥2 ♦Q108753 ♣QJ53: Pass.
After Multi-Landy 2♥
| (1NT) 2♥ (P) | |
|---|---|
| P | 2+♥, mostly 0–9 HCP |
| 2♠ | NAT, 6+♠ |
| 2NT! | Asks for the minor; short ♥ at any strength, or game interest |
| 3♣ 3♦ | NAT, 6+# |
| 4♣! 4♦! | SPL, 3+♥, 11+ HCP |
| 4♥ | S/O, 4+♥ |
Weak hands with 2+ hearts pass. With a singleton heart, advancer bids 2NT even when weak, to play in partner’s minor. With 3+ hearts and 9+ HCP it also bids 2NT. A 4-level minor is a splinter in that minor.
- ♠10876 ♥AJ3 ♦Q1094 ♣Q5: Pass.
- ♠984 ♥4 ♦Q875 ♣J10962: 2NT.
- ♠Q3 ♥Q982 ♦A10983 ♣74: 2NT.
- ♠92 ♥AQ10864 ♦Q64 ♣108: 4♥.
- ♠AK8 ♥K1073 ♦KQ932 ♣9: 4♣.
- ♠AKQ1093 ♥J10 ♦Q53 ♣104: 2♠.
After a balancing overcall
Advancer of a balancing Landy, Multi or Multi-Landy has passed 1NT itself. It bids as over the same overcall in the direct seat, but bids game less often. The probes gave advancer 0–14 HCP (247 boards per auction).
| (1NT) P (P) 2♣ (P) | |
|---|---|
| P | 6+♣, 3–8 HCP, seen on 4 boards |
| 2♦! | Equal length in the majors (rarely 1–2 apart), any strength |
| 2♥ 2♠ | S/O, the longer major, 1–10 HCP |
| 3♥ 3♠ | INV, 4+#, 3–14 HCP |
| 4♥ 4♠ | 4+#, 9–14 HCP |
With a 4+ card major and 12–14 HCP, advancer bid game on 16 of 34 boards, against 42 of 48 after a direct 2♣. With 9–11 HCP it bid game on 4 of 51, against 20 of 65. For example, ♠KQ54 ♥K2 ♦KQ876 ♣107 invites with 3♠ here but bids 4♠ over a direct 2♣.
| (1NT) P (P) 2♦ (P) | |
|---|---|
| P | 6+♦, 5–10 HCP, seen on 8 boards |
| 2♥ | P/C, 1–13 HCP |
| 3♥ | P/C, INV, 3+♥, 3+♠, 6–11 HCP |
| 4♥ | P/C, 3+♥, 3+♠, 10–14 HCP |
With 3+ cards in both majors and 9–11 HCP, advancer bid 4♥ on 8 of 40 boards, against 19 of 46 after a direct 2♦.
| (1NT) P (P) 2♥ (P) | |
|---|---|
| P | 2+♥, 1–14 HCP |
| 2NT! | Asks for the minor; short ♥, or 3+♥ and 9+ HCP |
| 3♣♦ | NAT, 6+# |
| 4♥ | PRE, 5+♥, 5–8 HCP, seen on 5 boards |
Pass and 2NT split as in the direct seat. No 4-level splinter appeared, and 4♥ came only from weak hands with 5+ hearts, e.g. ♠AJ7 ♥J87653 ♦6 ♣Q95.
| (1NT) P (P) 2♠ (P) | |
|---|---|
| P | 2+♠, 1–14 HCP |
| 2NT! | Asks for the minor; short ♠, or 3+♠ and 9+ HCP |
| 3♣♦♥ | NAT, 6+# |
| 4♠ | PRE, 5+♠, 3–8 HCP, seen on 5 boards |
With 3+ spades, advancer bid 2NT on 36 of 53 boards with 9–11 HCP and on all 38 with 12–14. A doubleton spade passed on 13 of 14 boards with 9–11 HCP. A direct 2♠ was not probed.
- ♠10876 ♥AJ3 ♦Q1094 ♣Q5: 2NT.
- ♠Q3 ♥Q982 ♦A10983 ♣74: Pass.
- ♠K ♥K95 ♦AQJ95 ♣10865: 2NT.
The overcaller’s second call
The overcaller’s second call shows shape, not strength. These probes dealt the overcaller the shapes of its first call with 9–17 HCP for Landy, 7–15 HCP for Multi, and 9–15 HCP for Multi-Landy (156–345 boards per auction).
Landy
Over 2♦, the overcaller bids its longer major at the 2 level and never jumps. With 4-4 it bids 2♥ (72 of 72 boards), and with 5-5 it chose each major equally often (18 boards each). Over the 2NT game try it bids the longer major at the 3 level, or 3NT with 4-4.
| (1NT) 2♣ (P) 2♦ (P) | |
|---|---|
| 2♥ | 9–17 HCP, ♥ at least as long as ♠ |
| 2♠ | 9–17 HCP, 5+♠, longer ♠ or 5-5 |
| (1NT) 2♣ (P) 2NT (P) | |
|---|---|
| 3♥ | 9–17 HCP, 5+♥, longer ♥ |
| 3♠ | 9–17 HCP, 5+♠, ♠ at least as long as ♥ |
| 3NT | 13–17 HCP, 4♥, 4♠ |
- ♠A954 ♥A764 ♦Q86 ♣K4: 2♥ over 2♦, 3NT over 2NT.
- ♠9864 ♥AQJ109 ♦A5 ♣Q8: 2♥ over 2♦, 3♥ over 2NT.
- ♠K8653 ♥AKJ2 ♦10 ♣874: 2♠ over 2♦, 3♠ over 2NT.
Multi
Over 2♥, the overcaller passes with hearts and bids 2♠ with spades. The raise to 3♥ needs a singleton or void: all 38 raises held one, and none of the 54 hands without one raised. With 6 hearts and a singleton, it raised on 12 of 25 boards with 12–15 HCP and 8 of 51 with less. With 7 hearts and a singleton, it raised on 17 of 25.
| (1NT) 2♦ (P) 2♥ (P) | |
|---|---|
| P | 6+♥, 7–15 HCP |
| 2♠ | 6+♠, 7–15 HCP |
| 3♥ | 6+♥, 7–15 HCP, 0–1 in a side suit, usually 12+ HCP or 7♥ |
| 3♠ | 7♠, 12–15 HCP, seen on 5 boards |
Over the invitational 3♥, the overcaller accepts from about 12 HCP. With hearts it bid 4♥ on 86 of 97 boards with 12–15 HCP and on 11 of 103 with 7–10. With spades it bid 4♠ on 20 of 40 boards with 12 HCP and on 64 of 74 with 13–15.
| (1NT) 2♦ (P) 3♥ (P) | |
|---|---|
| P | 6+♥, mostly 7–11 HCP |
| 3♠ | 6+♠, 7–12 HCP, rarely more |
| 4♥ | 6+♥, 11+ HCP, or less with a singleton or void |
| 4♠ | 6+♠, 12+ HCP, sometimes 8–11 |
- ♠92 ♥AQ10864 ♦Q64 ♣108: Pass over 2♥ and over 3♥.
- ♠108 ♥AK9753 ♦2 ♣AQ65: 3♥ over 2♥, 4♥ over 3♥.
- ♠AKQ1093 ♥J10 ♦Q53 ♣104: 2♠ over 2♥, 3♠ over 3♥.
- ♠KQ9762 ♥10 ♦K9 ♣K843: 2♠ over 2♥, 4♠ over 3♥.
Multi-Landy
Over 2NT, the overcaller names its minor at the 3 level at every strength, on all 817 boards. With 4-4 in the minors it bids 3♣ (13 boards).
| (1NT) 2♥ (P) 2NT (P) | |
|---|---|
| 3♣ | 4+♣, or 4♦ 4♣ |
| 3♦ | 4+♦, 0–3♣ |
The same holds over (1NT) 2♠ (P) 2NT (P).
- ♠8 ♥AJ973 ♦K1065 ♣J63: 3♦.
- ♠– ♥KQ1076 ♦A1095 ♣A1087: 3♣.
- ♠AKQ76 ♥9 ♦864 ♣Q1062: 3♣ over (1NT) 2♠ (P) 2NT (P).
Over their response
Wbridge5 also acts in fourth seat once the 1NT opener’s partner has used Stayman or a transfer. The double of an artificial bid shows the suit doubled. New suits are natural. Balanced strong hands pass; they have no penalty double here.
| (1NT) P (2♣) | |
|---|---|
| X | 5=♣, 9+ HCP |
| 2♦ 2♥ 2♠ | NAT, 5+#, about 10+ HCP |
| 2NT! | UNT, 5+♦, 5+♣ |
| 3♣ | NAT, 6+♣ |
| 3♥ 3♠ | PRE, 6+# |
| (1NT) P (2♦) | |
|---|---|
| X | 5+♦, 8+ HCP |
| 2♥! | Takeout, 4-1-4-4 (2 boards) |
| 2♠ | NAT, 5+♠, 9+ HCP |
| 2NT! | UNT, 5+♦, 5+♣ |
| 3♣ 3♦ | NAT, 6+#, 9+ HCP |
Over the transfer, Wbridge5 passes with hearts, the suit responder showed.
- ♠94 ♥Q732 ♦KQ ♣AJ1094: X over 2♣.
- ♠K3 ♥KQJ62 ♦10 ♣AJ865: 2♥ over 2♣.
- ♠K ♥K95 ♦AQJ95 ♣10865: X over 2♦.
- ♠K1093 ♥A ♦K874 ♣KQ62: 2♥ over 2♦.
- ♠AKQ1093 ♥J10 ♦Q53 ♣104: 2♠ over 2♦.
Not probed
- Opposing 1NT ranges other than 15–17 and 12–14, and advances over a weak 1NT.
- The overcaller’s second call after a balancing overcall, after a jump or a new suit by advancer, and later calls.
- Advances of a direct (1NT) 2♠, and balancing advances with 15+ HCP.
- (1NT) P (2♥), (2♠), (2NT) and (3♣), and Wbridge5’s calls over an opposing 2NT opening.