Source: acblunit391
Bridge Theory for the Practitioners by Amit Chakrabarti
In my discussions of 2/1 GF, attentive readers will note that one GF sequence, namely 1
– 2
sequence was not written about. This is a complex sequence and without an introduction to our minor suit bidding philosophy and general structure, nuances of the 1 – 2 sequence will be lost on the readers.
Hence, I am writing about our minor suit openings first. Before I write about specific sequences, let us first discuss what qualities a sophisticated bidding system needs to have. Such a bidding system must be able to:
1. Show the specific strengths of most common opening hands such as hands in the 12-14 range, 15-17 range and 18-19 range.
2. Show a way to GF early in minor suits if there is a fit.
3. Make NT contracts right sided.
4. Provide a detailed knowledge of our minor suit fit in competitive auctions.
Now look at the problems faced in Standard bidding for item #1.Consider two hands:
You open 1 and partner responds 1
. What is your rebid with these two hands?
Remember that your rebid of 3 is not forcing in Standard American. So a 3 rebid will work well for hand number 1 but not for hand #2. This is a big problem but we have a very clever fix for this in our system. Stay tuned.
Now, let’s visit items #2 and 3. In some sense they are connected. Perhaps that is because I have a strong aversion to playing inverted minor raises. So much so that in friends circle I call them “perverted” minor raises. Two reasons for my aversion:
Reason 1. Consider this hand: 
If you play inverted minor raise, your response to 1 is 1NT. That is just terrible bidding. NT is wrong sided and you are not rated to make 3N if the biding goes 1 – 1NT – 3NT.
Reason 2. If you are facing opponents as shrewd and sneaky as my partner, she will find a way to mess you up over with your inverted minor raise. This happened in a Kansas City tournament recently. The auction goes 1 – 2 which is alerted as inverted minor raise. White versus red, my partner comes in with 2
which I immediately raise to 3. Now you do not have any winning option left. Ultimately, our opponents made a frustrated 5 bid which went down 2 for +200 for us.
Just think how difficult it will be for her to come in if the auction went 1 – 3 showing a limit raise hand. On the other hand, if you bid 1 – 3 with a very weak hand, do you really think you can stop her from bidding? What are you trying to achieve then with your inverted raise structure?
So we do not play inverted minor raise. Our 1m – 2m is natural 6-9 count, with either an unbalanced hand or a balanced hand unsuitable to bid NT. Our 1m – 3m is purely invitational, limit raise type. But this causes another complication. We must have a way to show GF hands with minor suit fit. Yes, we do have that. Again, stay tuned.
Now, the last item. In a competitive auction, it would be really nice to know what kind of fit we have in our minor suit. If both of your 1 and 1 openings might show 3 cards, you often wonder about such fits holding a 4-card support for opener’s minor. To avoid this uncertainty, our 1 opening guarantees 4+ cards. Our 1 opening, however, can be done with just 2+ cards. This structure is becoming very popular and ACBL now does not require an alert on such a 1 opening, but just an announcement: “could be as short as 2 cards”. Also, note that you will open 1 with 2 cards only when you have a 4432 structure with 4 cards in both majors. This gives a high chance of finding a major fit and not to languish with your 2 card club suit.
Next I will discuss two other items. One our system handles magnificently, for the other our system development is in progress.
Recall that our 1NT opening ranges from a good 14 to bad 17. Given this range one does not need to bid 2NT over 1-minor with a balanced 11-12 hand. We can bid 1NT over 1 minor from 6-11 count. If opener has evaluated his hand to be a bad 14 and opened 1-minor, a bad 11 companion hand will not make 9 tricks. The other advantage of our structure is that now 2NT is one round forcing and shows 12-15 balanced hands with no 4-card major. Opener will almost always bid 3NT unless he has opened an 11-count hand with a 6-card minor suit in which case he will bid 3m. Finally, this makes 1 minor – 3NT non-system. My view is that 1m – 3NT is a self-preemptive bid against our own slam in a minor suit.