Quantumcat, on 2011-April-06, 20:46, said:
The reason is to make about 20 auctions clear instead of muddy. The only disadvantage is playing in a 4-3 fit at the two-level which could easily be a better spot that 1NT anyway. Besides the 20 auctions that become clear with this agreement, it is harder for the opponents to balance (opps having a fit means we must have one - but they don't have to have a fit, so it is dangerous to balance). This is actually the main attractant to playing Acol! (the inability of opps to balance effectively after for example 1♥-2♥.) In my experience, it is intermediate+ standard, not taught to beginners to whom it needs to be drilled into that you need 8 cards for a trump suit, but standard to anyone who has taken the time to think about it or has played with someone who has.
Sorry, but I have seen plenty of expert+ players who dont play it. The first time I encountered this is when I came to US less than a year ago, in ACBL and upon agreement. I agree that from time to time it would make your life easier on a partscore, but I would rather make sure to get to the right game/slam than optimise 1NT or 2
♥, with devoting a whole level of bidding to finding out if the support is true. With this logic you might argue it is good to support partner's major opening with a doubleton, or open 4 card major (which still works for some people, but it is far from standard)....:-)
Obviously if you have a regular partner and that works for you, great, but I think that experts generally have no problem showing 3 card support later on (unless they always want to be the captain in the bidding) or asking for it.
About balancing - it also goes for your partner, she/he also have no idea to what level to compete to, and having 5 card will end up bidding 3 level, just to show that the fit is guaranteed, or an opener with 4 card will bid again just to show 4 card.....
Quantumcat, on 2011-April-06, 20:46, said:
Next time you have a five card major you have responded with, and have a bidding problem and end up having to invent a suit or something, think about whether this auction might be a little simpler for you if you knew for sure partner didn't have three cards in your suit :-)
I never "end up having to invert", or rebid 5 card suit. My partner is intelligent enough to know that her bidding limits my and to what extent.
Quantumcat, on 2011-April-06, 20:46, said:
Just in case you don't know how usual auctions go with this standard agreement:
1♣-1♥
2♥-2NT = invitational with four hearts. Opener can pass (holding 3 cards) or correct to 3/4♥ (holding 4) or 3NT (holding 3)
1♣-1♥
2♥-3NT = GF with four hearts. Opener can pass (holding 3 cards) or correct 4♥ (holding 4)
I do know - just find it wasteful. For me long and short trial bids a much more useful conventions to get to right difficult games and avoid wrong slams.
Having another level of bidding - does wonders for the invitational + hands without the need to jump anywhere.....
3♦ showed 3 card heart support
3♠ showed ♣ fit and denies hearts will be trump suit
3NT showed singelton ace or king of spades, and therefore 1=3=5=4 or maybe 1=3=4=5 if you bid that way
4♦ can be cue-bid or if you prefer minorwood, whatever you play, responder does not bid 4♣ which would be passable
4♥ cue-bid
5♣ responder has tried hard enough
6♣ with two aces, and the king of hearts, seems like north has to bid the slam on this auction, if club ace was onside it would make