nullve

Yes, that was the point. Agree. I was pretty sure it wouldn't help your argument if I included more shapes. Anyway, here's an improved script: predeal west SKT62, DAKJ9642, CQT condition (hearts(south)>= 8 or (hearts(south)==7 and (clubs(south)>=4 or diamonds(south)>=4))) and spades(east)==4 produce 1000 action average "avg. # of tricks if W is declarer in a D contract" tricks(west,diamonds), average "avg. # of tricks if East is declarer in a S contract" tricks(east,spades) One run: avg. # of tricks if W is declarer in a D contract: 10.169 avg. # of tricks if East is declarer in a S contract: 9.903 Generated 150360 hands Produced 1000 hands Initial random seed 1620676152 Time needed 90.370 sec

It seems that systems where, roughly, 1♣ = NAT unBAL or <range_1> BAL 1♦ = NAT unBAL or <range 2> BAL 1N = <range_3> BAL, where range_1, range_2 and range_3 are different (presumably non-overlapping) hcp ranges, are increasingly known as "coded minors"*. (See e.g. . ) How did this name originate?

Dealer script: predeal west SKT62, DAKJ9642, CQT condition hearts(south)>= 8 and spades(east)==4 produce 100 action average "avg. # of tricks if W is declarer in a D contract" (tricks(west,diamonds)), average "avg. # of tricks if East is declarer in a S contract" (tricks(east,spades)) One run: avg. # of tricks if W is declarer in a D contract: 10.28 avg. # of tricks if East is declarer in a S contract: 9.81 Generated 31453 hands Produced 100 hands Initial random seed 1620637123 Time needed 13.130 sec

I'm a conservative 2♣ bidder (when playing standard 2/1), too. That has the effect that almost all unbalanced hands will, for any given shape, fall within a 4-point range (e.g. 22-25 hcp). The frequency table for 5341 hands, for instance, might look something like this Frequency : 22 48 23 28 24 17 25 4 26 2 27 0 28 1 29 0 30 0 31 0 32 0 33 0 Generated 4950969 hands Produced 100 hands Initial random seed 1620377251 Time needed 4.347 sec , where I've used the Dealer script condition hcp(north)>=22 and shape(north, 5341) produce 100 action frequency(hcp(north),22,33) This means that if the bidding goes e.g. 2♣-2♦(waiting); 2♠, then 2♠ has for all practical purposes even a (much) narrower range than even the "limited" openings in Precision. So basically Responder knows Opener's high-card strength (if unbalanced) and only needs to know about Opener's shape in order to judge whether to move towards slam or not. How, then, can the negative 2♥ response be useful? Well, iirc you like to be able to get out in 3♠ (maybe even 3♥) after 2♣-2♥(negative) when Opener has 5+S4+H, but other than that?

Why?

Often maybe, but not on average.

My distribution-around-the-table guesstimate: LHO: 2(43)4 Partner: 2524 RHO: 8(21)2 If correct (but close is often good enough), then there are only 18 total trumps and therefore only 18 total tricks if LoTT holds. If there are only 18 total tricks, then I want to defend 4♠X. If there are as much as 19 tricks (although I have no indication that there are), then defending 4♠X is still right if they are divided 10-9 in our favour. So I'd double (takeout in principle, although partner will apply LoTT and frequently pass) and let partner decide.

[hv=pc=n&s=s65hkq732dk5cj842&n=sakq32haj4daqj6c6&d=n&v=0&b=1]133|200[/hv] nullve(N)-nullve(S): 1♠(1)-1N(2) 3♣(3)-3♦(4) 3♠(5)-4♣(6) 4♦(7)-4♠(8) 5♣(9)-6♥(10) P (1) "10-21, 5+ S, unBAL" (2) "5-12, NF" (3) "19-21, (3)4+ D" (4) relay (5) 19-21, 5341 (6) puppet to 4♦ (7) forced (8) Parity Key Card Blackwood in H (9) odd # of key cards, no trump Q (10) contract Edit: Or if mikeh (below) is right that the North hand is really too strong for 1♠:

Correction: Leading the ♦Q at trick 2 cannot hurt, and will actually put the maximum pressure on LHO. (The discovery play can wait.)

[hv=pc=n&s=sak2hkq2dqj98ca43&n=sqj5haj6da732ck86&w=s7643h43dk64cjt97&d=s&v=b&b=7&a=2n(19-20)p6nppp]399|300[/hv] [hv=pc=n&s=sak2hkq2dqj98ca43&n=sqj5haj6da732ck86&w=s643h87543dk4cjt9&d=s&v=b&b=7&a=2n(19-20)p6nppp]399|300[/hv]

[hv=pc=n&s=sak2hkq2dqj98ca43&n=sqj5haj6da732ck86&w=s7643h7543dk64cjt&d=s&v=b&b=7&a=2n(19-20)p6nppp]399|300[/hv] [hv=pc=n&s=sak2hkq2dqj98ca43&n=sqj5haj6da732ck86&w=s643h543dk4cjt952&d=s&v=b&b=7&a=2n(19-20)p6nppp]399|300[/hv]

Why don't I make a discovery play instead, by losing a club trick early?

From a Robote Rebate 55 % tonight: [hv=https://www.bridgebase.com/tools/handviewer.html?lin=st||pn|nullve,Robot,Robot,Robot|md|4S874HAKQ95DAK2CQT,SQ62HJT86D976CA72,SJT95HDQJT85CK954,SAK3H7432D43CJ863|sv|b|rh||ah|Board%2010|mb|P|mb|2N|an|Two%20NT%20opener.%20Could%20have%205M.%20--%202-5%20!C;%202-5%20!D;%202-5%20!H;%202-5%20!S;%2020-2|mb|P|mb|3C|an|Stayman%20--%205+%20total%20points%20|mb|P|mb|3D|an|No%20major%20suits%20--%202-5%20!C;%202-5%20!D;%202-3%20!H;%202-3%20!S;%2020-21%20HCP|mb|P|mb|4D|an|5+%20!D;%2011-20%20total%20points%20|mb|P|mb|4S|an|2-5%20!C;%203-5%20!D;%202-3%20!H;%202-3%20!S;%2021%20HCP;%20no%20!HA;%20!SA|mb|P|mb|6D|an|5+%20!D;%2011-20%20total%20points%20|mb|P|mb|6N|an|2-5%20!C;%203-5%20!D;%202-3%20!H;%202-3%20!S;%2021%20HCP;%20no%20!HA;%20!SA|mb|P|mb|P|mb|P|pc|H6|pc|S5|pc|H2|pc|H9|pc|CT|pc|C2|pc|CK|pc|C6|pc|D5|pc|D3|pc|DA|pc|D6|pc|HA|pc|HJ|pc|S9|pc|H4|pc|HK|pc|HT|pc|ST|pc|H7|pc|HQ|pc|H8|pc|SJ|pc|H3|pc|H5|pc|D9|pc|C4|pc|D4|pc|DK|pc|D7|pc|D8|pc|C8|pc|D2|pc|S2|pc|DQ|pc|S3|pc|DJ|pc|SK|pc|S4|pc|S6|pc|DT|pc|C3|pc|S7|pc|SQ|pc|C5|pc|CJ|pc|CQ|pc|CA|pc|C7|pc|C9|pc|SA|pc|S8|]399|300[/hv]

1♠

[hv=pc=n&s=s763hkq83dk64cjt3&n=sa2ha7daqt92cak85]133|200[/hv] nullve(N)-nullve(S): 1♦(1)-1♠(2) 3♣(3)-3♦(4) 3♥(5)-3♠(6) 3N(7)-4♣(8) 4♦(9)-4♥(10) 4♠(11)-4N(12) 5♥(13)-5N(14) 6♣(15)-6♦(IMPs)/6N(MPs)(16) P (1) "10+, NAT(ish) unBAL" OR "20-22 BAL" (2) "0+, (3)4+ H, fewer than 4 spades unless GF" (3) "22+, 5+D(3)4+C" (GF) (4) relay (5) 2254, 6D4C(21), 6+D4+C0S or 8+D3(!)C (6) relay, prepared to bypass 3N opposite 6D4C(21) (7) 2254, NF (8) puppet to 4♦ (9) forced (10) Parity Key Card Blackwood in D (11) even # of key cards (12) trump Q ask (13) trump Q, ♣K, no ♥K (14) ♣Q ask (15) no ♣Q (16) contract

First things first: https://www.bridgebase.com/forums/topic/82267-rebid-with-6m4m-over-1m-2m/

From your recent Bidding decision thread: :blink:

But isn't that what most who say they play 2/1 actually do? Btw, playing strong reverses, what would you rebid with 1) ♠8 ♥AKQ3 ♦AKJ87 ♣872 over 1♦-1♠ 2) ♠8 ♥AKQ3 ♦872 ♣AKJ87 over 1♣-1♠ ? 2♣ in both cases?

2N is GF opposite a MAX reverse ("19-21"), so Opener can only bid 3♣ (P/C) with a MIN reverse ("16-18"). On this pair of hands I believe the correct auction (given the 1♦ opening) is 1♦-1♠ 2♥-2N 3N-P, where 3N is mandatory with a MAX reverse and this shape. A more practical approach could be to treat the opening hand as strong BAL and not open 1♦.

Agree.

Yes, sorry. MOSCITO is superficially a (s.2) system, but So I suspect they would have put MOSCITO in the same category as Blue Club if they had thought about it.

It seems to follow from the discussion in 'A system note' (p. 33 onwards), in particular the definition of class (s.3) systems on p. 33 and example (a) on p. 38, that Robson-Segal would not play any 3c raise over 1♦*-(2♠).

Agree. But on p. 200 of their book, Robson-Segal recommend using "Lebensohl 2NT" on K65 Q742 A653 K3 over 1♦-(P)-1♥-(2♠). So X, whether "support" (promising 3 H) or "takeout" (focusing more on the fourth suit and not absolutely guaranteeing 3 H), would presumably be the closest thing to a 3c raise in this position.

If you by "this system" just mean "transfers after 1♣", then the answer is Yes. But some try to make use of the extra bidding space by assigning a meaning to XX (like "10+" or "4+ D") and adjusting the remaining structure, but then they're obviously not playing "system on" in the sense of bidding just like after 1♣-(P).

Exactly which card did he discard on the second trump round?