Invitational Jump Shifts
#1
Posted 2005-May-16, 06:46
A partner and I are playing Precision, with 2/1 GF after 1M.
We are trying to decide the best use of jump shifts after 1M.
He doesn't like weak, I don't like Bergen. He suggests strong
or invitational with 6+. To me, if you play 2/1 GF, then strong
isn't that useful (comments?). Leaving invitational.
What do you think of it? It seems that it can patch a hole
after, say, 1S-1NT-3C, if you don't play WJS then 3C must
be weak.
What trump support should it show/deny?
Should 1H-2S be treated differently?
What you you play them as?
Peter
#2
Posted 2005-May-16, 07:02
1M - single-jump shift = inv+ splinter. If GF, then responder has a singleton.
1M - double-jump shift = void splinter. (GF by definition)
1M - 2NT = inv+ raise. By implication shows a balanced hand.
I know many people splinter with singletons and voids, but I find that in order to bid the thin slams and grand slams, it's quite useful to know.
If playing fit jumps you need to decide whether it shows 3+ card trump support or 4+ card trump support. If the latter, more descriptive but less frequent. You also need to decide on the range of the hand. Invitational plus seems to be useful.
After 1m, weak jump shifts seem to be quite useful.
#3
Posted 2005-May-16, 07:31
Mike Lawrence recommends 1M:2m as GF unless suit rebid, and 1M:3m as strong. This handles the below GF hands well and the SJS hands fairly well, but loses out on the GFs that can't make a SJS.
I play all jumps to the 2 level as weak (5-8 or so), now bidding and rebidding your suit is constructive (9-11) and a jump rebid is GF.
#4
Posted 2005-May-16, 07:46
I want this sequence:
1S 2C
2 any 3C
to be 100% GF. If partner has no support at all for my suit, he can bid NT, and I haven't lost anything.
Suppose the sequence continues:
1S 2C
2D 3C
3NT
I can now bid 4C to show something approaching a real "Rock of Gibraltar" strong jump shift. However, these come up so infrequently, I see little point in wasting a jump shift to show this hand type.
With the more likely hand, xx Kx xx AQJTxxx I like to get my hand over to partner as quickly as possible; with an intermediate jump shift.
Thus
1S 1NT
2D 3C
can show a similar length suit, but with a less good suit, so partner is less likely to get excited
1S 2C
2NT 3C
can be a mild slam try
1S 2C
2NT 3C
3NT 4C
can be a full blooded slam try
and 1S 2C
2NT 4C can be RKCB
The suit should be equal to that of a vulnerable pre-empt, and should deny 3 card support for the major opening.
#5
Posted 2005-May-16, 08:03
However, I still think playing 2/1 as 95% GF, i.e. Lawrence's style, is better. Now you can play 1M-3m as fit bid.
As for what trump support it shows, I think it should be doubleton at best. Otherwise you can upgrade hand and respond 2m then bid 4M.
Regarding 1H-2S, I stil like strong jump shift.
#6
Posted 2005-May-16, 08:19
#7
Posted 2005-May-16, 08:39
#8
Posted 2005-May-16, 08:44
pbleighton, on May 16 2005, 12:46 PM, said:
He doesn't like weak, I don't like Bergen. He suggests strong
or invitational with 6+. To me, if you play 2/1 GF, then strong
isn't that useful (comments?).
The case of 1M opener and precision 1D opener are different.
When you open 1D, you do not have available 2/1 GF, so a jumpshift to 2M can be quite useful to set trumps.
When you have a slammish single suiter in a major and pard opens 1D in precision, you want to set the trump suit ASAP, frcing pard to accept that suit as trumps even if he holds a void (this will rarely happen if you start with a 1M response and bid slowly:pard will always refuse your long strong suit, since he is always short there)
If you start with 1M, you need a tool to set the trump suit as GF BELOW game (4th suit forcing is horrible for that).
So, if you do not use the strong jumpshift, you are almost forced to use 1D-1M-2C/D-3M as GF with selfsufficient suit (the strong JS-type hand) and not as invitational (as I said, using 4sf here is almost always a losing option).
This treatment is ok if you use the immediate jumpshift as invitational.
#9
Posted 2005-May-16, 08:51
Chamaco, on May 16 2005, 03:44 PM, said:
This treatment is ok if you use the immediate jumpshift as invitational.
Or if you use it as weak!
#10
Posted 2005-May-16, 08:53
MickyB, on May 16 2005, 02:51 PM, said:
Chamaco, on May 16 2005, 03:44 PM, said:
This treatment is ok if you use the immediate jumpshift as invitational.
Or if you use it as weak!
Right, the meaning of 1S followed by 2S can be switched
#11
Posted 2005-May-16, 09:02
Also, the 14-16 1NT (or 13-15) opening often used in precision fits very well with this, as you can pass 1M-1NT with all balanced hands.
I think that mini-splinters or fit-jumps are very valuable when they come up, but this is not very frequently. Contrary to invitational jump shifts, they don't really make the rest of the structure better.
BTW, is there anybody that has experience with a duo-jump shifts, i.e. 1M-3m as showing either a weak jump shift or a mini-splinter? I've seen this being used in a Dutch system called "snowface", the author claims that opener rarely has any problem identifying which kind of hand partner has.
- hrothgar
#12
Posted 2005-May-16, 09:08
Quote
If you play 2/1 absolute GF and 1NT is nonforcing, what do you bid with:
x-AKxxx-QJx-Jxxx
when pard opens 1 spades (10-15) ?
I suppose noone will suggest using 3 hearts as inv JS with this hand , and 2H is not an option (absolute GF).
Then one needs a more complcated structure than plain 2/1, a little like ETM full 2/1.
Quote
Some time ago, I asked whether it could make sense a 2-way Jumpshift as showing EITHER a natural strong JS OR a fitshowing JS.
The only person that seemed interested was Ben (inquiry), but in any case I had no chance to give it a try so far...
#13
Posted 2005-May-16, 09:19
Thus, we have the single jumps free for whatever. I'm sure this method is not playable with an opening bid that can be 11-20 however. The other advantage of passing with some values (but a misfit) is that it makes it more dangerous for opponents to balance or compete.
#14
Posted 2005-May-16, 09:36
Chamaco, on May 16 2005, 10:08 AM, said:
x-AKxxx-QJx-Jxxx
when pard opens 1 spades (10-15) ?
I suppose noone will suggest using 3 hearts as inv JS with this hand , and 2H is not an option (absolute GF).
I bid 1NT, not forcing. Perhaps I misunderstand your point, or perhaps my "non-forcing" suggests up to 10 HCP, but this is not what I meant.
- hrothgar
#15
Posted 2005-May-16, 11:17
Why are IJS horrible? Because
1. They don't completely solve the problem of how to bid invitational hands - there are plenty of hands where you have a long suit but you're not sure you really want to play in it.
2. Opener often doesn't know what to do, and doesn't have enough space to find out.
Having said that, when I play 2C as forcing to game, I play IJS. But they always seem to get us bad results.
#17
Posted 2005-May-16, 11:39
mr1303, on May 16 2005, 12:26 PM, said:
Dunno. Possibly because the only decent solutions to this problem aren't allowed in EBU competitions until next year.
Actually, how about playing fit jumps over 1♥, weak jumps over 1♠?
#18
Posted 2005-May-16, 17:20
david_c, on May 16 2005, 06:39 PM, said:
mr1303, on May 16 2005, 12:26 PM, said:
Dunno. Possibly because the only decent solutions to this problem aren't allowed in EBU competitions until next year.
Go on then David, elaborate
#19
Posted 2005-May-16, 17:27
1♠ - 1NT (forcing) - 2♦ - 3♣
If 3♣ promises invitational values, then you're forced to pass with a distribution like 1336, even though it will often be the case that 3♣ plays better than 2♦. However, if 3♣ carries the wide range of something like 6-11, partner will often be stuck. Another option is to play the jumps as something like 6-9... however most people I know who play "weak jump shifts" tend to use them on weaker hands than these.
My personal preference is to reverse the meaning of 2♦ followed by 3♦, and the direct 3♦ jump. So I'm playing "2/1 except suit rebid" instead of 2/1 GF. The reasoning is, take the following four hands:
(1) Ax KJx KQJxxx xx
(2) xx KQx KQJxxx xx
(3) x KJxx KQJxxx xx
(4) x AKxx KQJxxx xx
Playing 2/1 GF with intermediate jumps, you bid 2♦ followed by 3♦ on the first hand to force game. Notice that you're bidding 3♦ pretty much regardless of opener's second call -- you're not going to raise hearts in a 4-3 fit or spades on a 5-2 (assuming opener's 2♠ rebid doesn't guarantee six). On the second hand, you make an intermediate jump to 3♦. So far so good.
But hand three presents a problem. If you bid 3♦ (intermediate) it may be hard to find a heart fit. I wouldn't guarantee partner will bid 3♥ over this on four, especially with minimum values. Of course, if you bid 1NT (forcing) you're now really stuck if partner rebids 2♣ or 2♠, because you've already DENIED a single-suited invite with diamonds by not bidding 3♦ to begin with. Hand four is easy enough, you bid 2♦ and then you can rebid 3♦ or 3♥.
Playing 2/1 GF-except-rebid with single-suited GFing jumps, you bid 3♦ on the first hand. You haven't really lost much, because you were going to bid 3♦ on your second call anyway. On the second hand, you bid 2♦ followed by 3♦. Again no problems.
But hand three is now easy. You bid 2♦. If partner bids 2♥, your hand re-evaluates to a game force anyway and you can bid 4♥ (picture jump) to perfectly describe the hand. If partner bids something else, you rebid 3♦ (invitational).
Hand four is also no problem -- you start by bidding 2♦ and then if partner bids 2♠ or 2NT you can rebid 3♥ (natural, game forcing reverse with 4♥ and 5+♦).
a.k.a. Appeal Without Merit
#20
Posted 2005-May-16, 18:32
MickyB, on May 16 2005, 06:20 PM, said:
david_c, on May 16 2005, 06:39 PM, said:
Go on then David, elaborate
When I've finished writing up my system I'll let you know.
But what I was referring to is that we're not allowed an artificial 2♣ bid which is not quite game-forcing, such as the one played by Ben.