Watching this discussion, I saw two good statements and some horrible.
To Mr Yzerman: This is a place to discuss. It is not a place to tell and not to listen. And it is not a place to use words like: You should read more careful.
Please follow your own advice. And while doing so, better think about Rados post and answer later.
For 2/1: Good guys who miss a game just abuses the bid. But the good guys from the original post who missed 7 spade are a good example?
Like Rado said: Every Convention has its ups and downs.
But to compare a convention, which shows exactly 45 in the majors with 11-15 HCPs to a multi 2 Diamond is childish.
You have to compare the whole structure.
So, when do you don`t need flannery:
Whenever you have an uncontestet auction.
After 1 Heart-1 Spade 2 Spade you showed 4-5+ in the majors and 11-15 HCPs. So, no gain with flannery.
You may gain in an competetive auction, where you are allwod to show your majors quick and else have problems to show them latter.
F.E. : 1 Heart (3Club) pass pass...
This definetly is the one and only big advantage.
You are quick in and showed your hand. And that really is a big big advantage.
What else will happen, lets look at your comments:
a) I REFUSE to rebid a 2 card club suit after forcing NT
Great. Pd refused to bid 1 Spade or two heart, so you have no fit. Ok, this is a problem in 2/1. But it is no problem in SAYC or other normal systems. PD will bid 1 NT and play there....
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I REFUSE to rebid a relatively poor 5 card heart suit
Aha, so you prefer to be in 2 Heart Flannery then in two heart after 1 Heart-1NT -2 Heart? The one and only advantage is, if pd has something like 3145 and can correct to 2 Spade and play there. But then again, with simple SAYC you will play 1 NT, so no gain for Flannery there, just a smaller loss.
c) Constructive preemptive value
..Had been modern in the days of Goren. Nowadays most top pairs uses weak preempts. Any ideas why?
d) The ability to play 4H or 4S from either hand (via South African xfers)
If you open 2 Heart, there is exactly no chance to play 4 Heart from pds hand.
e) Responder has a roadmap regarding hand evaluation
Like after 1Heart 1 Spade 2 Spade? Wow
f) Constructive game/slam bidding
Same answer...
Why do I prefer Flannery over Multi?
a) My suits are disclosed (no guessing or asking)
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Luxury of playing @ 2 level in a misfit (4/3 or 5/2)
Compared with 1 NT in a natural system is this exactly no gain, it is just a loss.
c) I dont really care about preempting a hand with 5 card major and 4 card minor (In the back of every bridge players mind when they open 2H or 2S Dutch Multi, there is the fear of going for phone number - not the case with Flannery).
You donīt need to care and you donīt have to play it. But again, look at the modern preempts. You donīt need to be modern and you donīt need to be successful. But funnily, the successful players out there donīt use many sound openings, nor sound preempts. So maybe there are advantages to bid a little less sound then you do? (Of course you better learn to play cards and to play good boards after some casual desasters before getting light like Mr. Bergen)
You forgot d: Flannery shows 11-15 HCps and a weak two 5-11. I always prefer to have more HCPs.
Btw: I play flannery too, but just in fourth seat, when there is no other sense for our weak 2 Heart bid.
But I gain a million imps more with other 2 Diamond and/or 2 Heart opening bids.
And again, just check the real good guys. I know eaxtly nil who still play flannery. Do you know one?
Kind Regards
Roland