Suppose the auction begins 1C-Pass-1NT-?
The actual auction was Pass-Pass-1C-pass-1NT, and this could matter, but not for the point I want to make.
After 1C-Pass-1NT, what are the pluses and minuses for 2C being natural, presumably showing a strong six card suit such as KQJxxx.
It was observed that the NT bidder also has some clubs.
If we think about it, that's a good thing. Let's suppose, as I believe people were supposing, that the NT bidder has at least three clubs. And let's suppose the opponents to not open 1C on a doubleton.
The conclusion is that if partner has one club then the outstanding clubs are 3-3 since we have agreed that each of the opponents must have at least 3 and there are only six clubs missing.
Compare that with an auction that begins 1C-Pass-1S. For all we know, the club opener could have five clubs. So coming in with a natural 2C over this auction is more dangerous than it is when the auction begins 1C-Pass-1NT.
It's also interesting when we have a strong six card heart suit. Suppose the auction starts 1C-Pass-1NT and we have KQJxxx in hearts. Suppose partner has a stiff heart. When our suit was clubs, we have seen we can now expect a 3-3 split in trumps. Not so when our suit is hearts. Perhaps partner has one heart. There is no reason to be confident the 1NT was not on 3=2=4=4 shape. Maybe he would bid 1D with that, maybe not.
I am going to browse around some to see if there is a consensus on whether 2C, after 1C-Pass-1NT, should be Michaels or natural, but I found it interesting that placing 3+ clubs with the NT bidder actually makes the natural 2c bid safer because the suit must therefore split well. Of course 4-3 is possible if pard has a void, but that's the worst that can happen. After 1C-Pass-1H, the outstanding clubs could be 5-2, or even 6-1.
Now about that assumption that after 1C-Pass-1NT we can assume the NT bidder will have at least three clubs. He will not have a major, or maybe a weak major and 4=3=3=3 shape, but could he be 3=3=5=2? I think he could. Or at least I could. If my hand is "notrumpy" and I have 8 or 9 highs, bidding 1NT seems very reasonable. It takes up some room to obstruct the opponents, it is likely NT will be a better place to play than diamonds, and if partner has long clubs he can bid them. So I would say that after 1C-Pass-1NT it is highly likely, but not really certain, that the NT bidder has at least three clubs.
As always, lesson hands can be useful.
On the actual hand, I had to choose a call after 1C-Pass-1NT and my shape was 5=5=3=0. I chose X, partner responded 2D, we were in a 5-3 diamond fit instead of our 5-3 heart fit, the opponents went on to 2NT. Partner was 1=3=5=4. My hand was Qxxxx, AKxxx, xxx, void. So the question was whether I could have bid 2C Michael's. As mentioned, the first call was Pass on my right so I might have opened. But I am not opening 1H when I am 5-5, I am not enthusiastic about opening that 1S, and if I do open 1S I am not so sure I want to be bidding 1H later. The opponents have a 9 card club fit and if they get to 3C, and then pard doubles because he thinks I actually have something for my opening bid, I will not like my choices of pulling to 3H or hoping we can set 3CX. I don't recall all four hands accurately but I doubt that we would either set 3C or make 3H.
Anyway, Larry Cohen likes to play that after 1C-pass-1NT then 2C is Michaels. But I am pretty sure there are others who differ. (Other than me).
