[Zelandakh]

bluecalm, on 2014-March-18, 08:44, said:

Yeah, I just made two. I made many more in the past and I am confident about my conclusion. I am happy to do more if you have specific examples but in the end you will probably have to believe me or do research yourself.

Why not go with a hand like: ♠Axx ♥43 ♦AK654 ♣543? I assume when you calculate scores for your balanced 12 opposite 6-10 you are taking account of whatever the opps might make, since this sounds like a part-score scrap hand.

[bluecalm]

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Why not go with a hand like: ♠Axx ♥43 ♦AK654 ♣543?

Here you go:

vulnerable: o
IMPs: 1.242
MPs: 0.639
vulnerable: NS
IMPs: 1.732
MPs: 0.639
vulnerable: WE
IMPs: 1.242
MPs: 0.639
vulnerable: WNES
IMPs: 1.732
MPs: 0.639

The difference is huge and it's clear why: diamond partscore is much better than spade one as partner is max 4-3 in majors so he has 4+ diamonds quite often.
If the choice was between playing 2S and 1N then 2S would be a winner (46.5% and -0.26imp for 1N) but additional option of signing off in 2D/3C tip the scale considerably.

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I assume when you calculate scores for your balanced 12 opposite 6-10 you are taking account of whatever the opps might make, since this sounds like a part-score scrap hand.

No, I am just comparing strategies of bidding 1N and 2S. While there are arguments for both in competitive auction I don't think it's clear which one have an edge. If they intervene after 1NT we can still bid 2S. If they bid something after 2S we have to be careful to not to go to 3S if partner often might have 3 on regular basis.

Also to the point from previous post:

Quote

The main advantage of supporting is probably to releave partner of the problem of wether to rebid a fivecard-suit after openers 1NT (or 2m) rebid

If you only raise with perfect hands (ones with xx doubleton) like in the article from Weinstein linked above then still partner have 3 spades very often for 1NT and passing it with 5 spades is very bad (especially at matchpoints).
It's difficult problem to solve. I think the best strategy is to bid 2C with 5 clubs and 1-(34)-5 after 1S especially in context of non-Walsh bidding but even when playing Walsh I think it's better to bid 2C and have 1N guarantee 2 cards.
After 1D - 1S it's even tougher as now 1-4-4-4/1453 shapes have no other rebid. I did some simuls there too and concluded that bidding 2S is only better (marginally) with very strong suits but it's still close.

[jogs]

bluecalm, on 2014-March-18, 10:50, said:

If you only raise with perfect hands (ones with xx doubleton) like in the article from Weinstein linked above then still partner have 3 spades very often for 1NT and passing it with 5 spades is very bad (especially at matchpoints).
It's difficult problem to solve. I think the best strategy is to bid 2C with 5 clubs and 1-(34)-5 after 1S especially in context of non-Walsh bidding but even when playing Walsh I think it's better to bid 2C and have 1N guarantee 2 cards.
After 1D - 1S it's even tougher as now 1-4-4-4/1453 shapes have no other rebid. I did some simuls there too and concluded that bidding 2S is only better (marginally) with very strong suits but it's still close.

1♣ - (pass) - 1♠ - (pass) , ?

Weinstein's guideline seems reasonable. He didn't discuss rebids with 1=4=3=5. I tend to rebid 1NT with that pattern. Against this set of NT rebids, one should only rebid five card spade suits with solid spades. QJT98, but not AK432, would rebid 2♠. Only rebid spades with hands which need spades as trumps to be assured spade tricks.