pescetom, on 2019-September-20, 06:50, said:
Thanks. Unless I miss something it doesn't seem a very good agreement, a more common 2♠ showing 5-card spades and a minor would have worked better. At the other table EW found the spades fit which doesn't seem likely with this agreement (if the major can be 4-card as it appears) and indeed did not happen. And after 2♦ the situation will be even more precarious as there is no room to enquire for the major.
I'm not really defending the use of 2
♣/2
♦ to show that suit and a minor. In fact, I've been playing Multi-Landy which uses 2
♠ as showing spades and a minor. But, if you don't have a spade fit, you have to go to the 3 level to find a minor suit fit while Robson-Forrester can find a minor suit at the 2 level. Every systems has strengths and weaknesses.
After 2
♦, if advancer doesn't like diamonds and would like to play in overcaller's major instead of diamonds, they bid 2
♥, pass or correct. Seems very straightforward to me.
I'm just speculating, but there was no attempt to find a major because a determination was made that
1) 4 of a major has no chance of making
2) Exploring for a major fit gives more bidding space for the opponents
3) How do you explore for a major? And if overcaller has hearts, do you want to sacrifice in hearts or clubs. If you sacrifice in spades, you will likely be doubled.
4) 4
♣ is about as preemptive as you can afford (and maybe more), but gives opponents room to make a bidding mistake.