[awm]

straube, on 2012-January-08, 09:42, said:

So I'm wondering if IMPrecision can extend it's 2-way idea a round further.....


1C-1D......

.....1H-17-20 NT or hearts
..........1S-DN or GF balanced or possibly a few rare shapes
...............1N-17-20 NT
....................a system based on transfers to allow relay for a few shapes, signoffs for the DN and bal vs bal bidding
...............other-hearts
....................S1 (usually)-GF balanced
..........1N etc-relays 7+ RP shapely hands at +2 or better
.....1N-21-23 balanced or semibalanced

You could do this, but I'm not convinced it's better. Some of the issues:

(1) By far the most common 1♦ "positive" is the balanced hand. You will have some issues when opener has hearts and responder is balanced by playing this way, because you cannot make full use of your space. For example 1♣-1♦-1♥-1♠ and opener cannot bid beyond 2♥ on most hands because of the double negative possibility. Opener may have to immediately show values on some hands to avoid a pass from the double negative (awkward for relay). The step bid cannot always be the relay because the double-negative may need to be able to correct the strain (i.e. 1♣-1♦-1♥-1♠-2♦ and 2♥ probably isn't the relay). I think you are losing quite a bit on these sequences, both in complexity and space.
(2) When responder has a shapely GF, you have saved about a step.. but you have wrong-sided some contracts, reduced the information available to responder (i.e. if you have 6(322) opposite 1NT you can just set spades and cuebid but now you have to resolve shape in case opener has hearts so you do lose something here)... and arguably once you are "+2" relays are not great in any case. In fact a part of the reasoning for our methods that hasn't been discussed is to avoid "+2 relays" in uncontested auctions always!
(3) You lose some space in describing shapely negatives (i.e. 1♣-1♦-1♥-2x in my methods) which can be quite helpful when they come up. You also lose the ability to show a negative with a heart fit right away (1♣-1♦-1♥-2♥) which can help in finding shapely games on low values. Note that 1♣-1♦-1♥-1♠-2x-2♥ presumably could contain a wide range of heart holdings (not necessarily a real fit) in your method.

[straube]

Which of your balanced hands with four or more spades rebid 1S after 1C-1D? Is it 21+? 17+? 4+ spades? 5+ spades? I would think 5 spades only.

If you had to play the change I proposed, which hands would rebid 1H (balanced 17-19) and which hands would rebid balanced 1S? 4 spades? 5 spades? I would think 5 spades only.

Or perhaps I would have to give up showing balanced with spades in order to show S/H hands...or more of them.

If I have the time, I want to look at frequencies, but those frequencies depend on what the answers are to those questions.

I think you made some good points. For example, it's rather nice that 1C-1D, 1H-2H shows 4 hearts with a DN. Not always nice as sometimes opener has the big balanced hand without a heart fit and retreats to 2N. But usually nice.

You have a nice way to show a spade preference after 1C-1D, 1H-1S, 2C. I would definitely have to assign 2D as a relay; no getting around that one. 1C-1D, 1H-1S, 2C-2H DN no fit is bad, but no worse really than what Atul and I presently play. So I worry about the S/H hands, but I'm not overly concerned about the giant heart hands.

I'm not worried about 1C-1D, 1H-1S, 2D-2S relaying because we're +0.

I don't like +2 either, but I'm concerned about showing all of the 5431s and 6421s etc. I think if partner has 17-20 balanced and knows partner's shape (say 5431) and knows he has at least 7 RPs, that some good can come of that. And when responder has like 9 or 10 QPs, he can reject sign off attempts.

1C-1D, 1H-2C/2D/2S as DN 5/5s feels wrong to me.

Hope you don't mind poking at your system. Atul and I are pretty excited about it.

[awm]

(1) We don't really rebid 1NT with five-card major after 1♣-1♦. If responder has GF we are much better to bid 1M (where we can relay, and in fact we are at +0 on one-suiters). If responder has garbage we are very often better to play 2M (even on a 5-2) than to play 1NT. One can make exceptions for really terrible major suits of course.

(2) We will rebid 1NT with 17-20 and any 4432, 4333, or 5m-(332) shape. This is regardless of major suit holdings. Bidding 1M here is not great because our balanced hand relays are not that efficient (thus benefit from more limited range of strength, which we see in many sequences), and because our bidding opposite DN tends to be better if we rebid 1NT on these.

(3) If we have a four-card major and a balanced 21+, we rebid that major. This helps us sometimes (i.e. finding spade fits after 1♣-1♦-1♠ is easy, and usually we are willing to bid to the field 2NT if we have to) but mostly it's to reduce the load of balanced hands on the 1♥ rebid (it improves our relay structure).

The 1♣-1♦-1♥-2♥ auction is normally not on utter trash (i.e. usually hands with like 2-4) so we are pretty safe if opener rebids 2NT natural over this (in fact we are usually going to game opposite 21+ balanced on these hands). It helps a lot to show a real heart fit right away when opener has hearts and it doesn't really cost opposite the balanced hand because it's a big one.

The problem you are going to have is that if you play 1♣-1♦-1♥-1♠-2♣ the way I do, you have to cover five-four and five-five hands in three suits (opener can have any second suit); you're going to be at +2 fairly often here I think. You can reduce the pressure somewhat by offloading some hands (say 5♥/4♦) into 2♦, but then you are behind there also and have some issues because DN responder doesn't know relative suit length too. Further you're losing responder's call when he has DN with a long string of spades, which is actually a potential game contract (and very often 2♠ is the best partial).

If I had to play your change, I wouldn't really want to bid 1♠ with four spades and a balanced 17-19 (because I can't get to 1NT any more) and would probably just bid 1♥ on all min balanced hands.

[straube]

I'm thinking about....

1C-1D,
.....1H-H various or 17+ balanced
.....1S-S/m or 5S bal
.....1N-H/S

Now we have to rebid 2N with 21-22 or so.

What do you think of this tradeoff?

[straube]

1C-1D, 1N would include the 3-suited short minor, of course.

Another thought would be to reassign 1C-1D-2H to 4S/5H (or the reverse), but I'm favoring 1N rebid as both majors (partly because it handles 3-suited).

[awm]

straube, on 2012-January-08, 12:05, said:

I'm thinking about....

1C-1D,
.....1H-H various or 17+ balanced
.....1S-S/m or 5S bal
.....1N-H/S

Now we have to rebid 2N with 21-22 or so.

What do you think of this tradeoff?

Well the disadvantages are small: (1) I do like bidding 1NT on the big hands, both for safety and because I can invite in a minor and stuff (2) You still lose responder's natural DN 2♠ sometimes. (3) There are still some issues when opener has a really big hand with hearts opposite a balanced GF, since opener cannot make a NF 2♦/2♥ call.

The advantages are small too though: (1) Removing balanced with four spades from 1♠ helps a little on relays, but you're still usually +1. (2) It is a little easier to bid three-suiters with both majors by starting with 1N.

The main point is that you seem to think it is a very substantial win to play relays at +2 with relayer's hand being unknown, rather than to play notrump "systems on" over a natural and limited 1NT bid. I do not agree with this, and think it is at best a wash and quite possibly actually better to play notrump "systems on" in this situation.

[straube]

I looked at frequency rebids after 1C-1D for 58 hands. Fibonnaci isn't everything, but I think it's a good indicator. Something looks out of kilter with both methods, but I'm still interested in rebidding 1H with the balanced hands.


1H as bal or hearts.........57%................1H as bigger or hearts...........17%
1S natural.......................24%................1S natural..............................30%
1N as majors...................7%.................1N as 17-20..........................40%
2C as natural...................7%.................2C as natural...........................7%
2D as natural...................3%.................2D as natural...........................3%
other................................1%.................other.......................................1%

[straube]

I'm thinking we're at +2 for most 2-suited hands, but we're only +1 for the 1-suited hands and for C/D. Hopefully, when responder has a major, we will have a fit and have extra room to relay on the way to 4M.

1C-1D, 1H

1N-4+ hearts
.....2D-4+ spades at +2
..........2S-3-suited, short minor at +2
.....2H-4+ clubs at +2
.....2S-single-suited at +1 (no 5332)
2C-4+ spades at +2
2D-C/D at +1
2H-C at +1
2S-3-suited, short major at +1
etc-D at +1

[awm]

straube, on 2012-January-08, 13:08, said:

I looked at frequency rebids after 1C-1D for 58 hands. Fibonnaci isn't everything, but I think it's a good indicator. Something looks out of kilter with both methods, but I'm still interested in rebidding 1H with the balanced hands.


1H as bal or hearts.........57%................1H as bigger or hearts...........17%
1S natural.......................24%................1S natural..............................30%
1N as majors...................7%.................1N as 17-20..........................40%
2C as natural...................7%.................2C as natural...........................7%
2D as natural...................3%.................2D as natural...........................3%
other................................1%.................other.......................................1%

I disbelieve these statistics. To see that they are wrong, consider that virtually every hand that rebids 1♠ would rebid 1♥ with the majors reversed (small number of exceptions like 5/5 majors and 4M-5♣) so the odds of 1♠ rebid cannot be this much higher than 1♥ rebid. Here are my stats for IMPrecision rebids after 1♣-1♦:

1♥: 25.8%
1♠: 27.0%
1N: 29.3%
2♣: 9.4%
2♦: 6.0%
other: 2.5%

The Fibonacci thing doesn't really apply here, because the relay over both 1♥ and 1♠ is 1NT so you want equal space to resolve. Also, we are not normally relaying out opener's shape after the 1NT rebid (plus the number of patterns in 1NT is actually rather small and further they are patterns that tend to play similarly, it's just that balanced hands are very frequent).

[straube]

I may have tabulated some hands wrong and I only looked at fifty-some, but thanks for the true figures. Here's what I got for the 2 methods after 1C-1D, 1H. If you have better statistics I would be interested to know them. Results are in hands and there are more for the tweak because more 1H rebids.

IMPrecision

1S- 12
1N-17
2C-1
2D-0
2H-1
2S-1

tweak

1S- 56 hands
1N-5
2C-4
2D-2
2H-1
2S-2

[straube]

I think I give up. I like the branching IMPrecision gets after 1C-1D and I also like the branching it gets at 1C-1D, 1H. I still have the idea to use 1C-1D, 1H-2L for some relays, but responder bidding 1N to establish a GF with usually a balanced hand makes a lot of sense to me. Thanks for putting up with me and I've really enjoyed the IMPrecision notes.

[Zelandakh]

straube, on 2012-January-07, 10:57, said:

ok, so putting these side by side. IMPrecision is guesstimated and generic symmetric 1D response is 0-7 and 1H response is all of the S+ hands and 1S is all of the balanced and both minor hands....

.....................Fibonacci.............SCREAM...............IMPrecision.................straw man.................generic symmetric 1D=0-7
1D...................41.......................36........................37..............................28.............................57
1H...................25.......................41........................24..............................41.............................14
1S...................16.......................16........................22..............................20.............................20
1N....................9.........................1.........................12...............................4..............................4
other................9.........................6..........................6................................7..............................5

Again, not saying Fibonacci is everything...other considerations like which sequences are most important plus one would expect to spend more room than Fibonacci would suggest because one's other goal is to take up space before the opponents do.

Did you notice on this graph that if you switch the 1♦ and 1♥ response in "straw man" you get something almost exactly like your Fibonacci numbers? I am not saying this ia a good idea, just an interesting observation.