My first thought about "what does the XX mean?" was that I have never discussed it with anyone, and that has never mattered because it has never come up. Well, my very forst thought was that I don't understand exactly what is being asked. I could imagine
1m - pass - 2m - pass
2M - X XX
or
1m - pass - 2m - pass
2H - pass - 2S - X
XX
I had assumed the first, others seem to be assuming the second.
So let me go with the first for a moment. It seems like it won't much happen, and it hasn't. Just take
1m - pass - 2m - pass
2M - X
What does the doubler have? He lacks the values to bid 1M over my 1m but now wants to double my 2M? The double is fr a lead no doubt but he cannot have, or is very unlikely to have, a strong five card suit. If he has a strong four card suit I appreciate his letting me know about that and I will alter my bidding and play accordingly. Now if i have a stopper in M and my lho has a good four card holding in M it seems unlikely that partner is also going to have a good holding in M so maybe XX should just be a general game force, or perhaps even a game force with a shortness in M.
But really the situation has never come up in the first auction, nor do I recall it aver coming up in the second.
This all relates to Jack's comments, namely that there are more basic issues to discuss when playing inverted minors. I recall reading an expert opinion that inverted minor raises are a modest plus for pairs that have discussed the details and a modest or sometimes substantial minus for pairs that have not discussed the details.
For example, this is taken from BWS:
"After a strong single minor raise, opener can: (1) show willingness to play in three of his minor by bidding it; (2) bid two notrump natural (but the bidding is forced to three of the minor); or (3) bid a new suit (after which the bidding may still stop at three of the agreed minor)."
How many pairs have discussed even this much? So 1m-2m-2NT is forcing for BWS. I am pretty sure that the bots play this auction as non-forcing. I play it as non-forcing with my usual f2f partner. I think playing it as forcing is probably better, but that requires some discussion also. My point is that the auction 1m-2m-2NT arises often, the XX auction I cannot recall ever arising.
I have had reasonably decent results with inv minor auctions. My preferences for 1
- 2
:
My 2
call could be on four cards, but only if I have game forcing values. If I have more modes values, maybe 10-12 highs, I will have five diamonds and I expect my next call to be 3
, however 1
- 2
- 2M - 2NT is a possible continuation and is passable.
If the suit is clubs rather than diamonds, it's pretty much the same but now I might want a little more shape or a little more strength.
Also, the auction 1m-2m-3m shows a minimal somewhat shapely hand for opener.
This seems to usually work out ok. BWS plays that 1
- 3
shows clubs and with invitational values. I think, but I am not sure, that the bots do the same. Using 1
- 3
as an artificial raise of diamonds of some particular strength has its merits, but so does the BWS approach.
As to whether the opening 1
needs to show four cards, views have differed forever. My preference is that a 4=4=3=2 shape be opened 1
. I realize it can cause difficulties but having to open it 1
can also cause difficulties. Using the inverted minor raise the way I lie, then when partner opens 1
on a three card holding we might end up in 3
on 5-3 fit but not in a 4-3 fit since, when I have only four cards, I plan on going on to game somewhere.
Short version: There are many different ideas on how to play inverted minors, the most important thing is to talk it through. The meaning of the XX could be fairly far down on the list of things to discuss.
One more thought about opening 1
on three cards. Suppose the auction begins 1
- 1M - 1NT, a pretty common auction. Partner has four or maybe five diamonds since he clearly lacks four card support for M. Usually it becomes clear early on whether the 1
opening had to be on four. Not always, but almost always. I can't recall the last time it caused me a problem.