N E S W
/ 1C / 2C
double: for penalty
pass: denies a stopper in D
2H/S: garantees a stopper in D
and the suit you bid.
2NT: natural and garantees all
stoppers in unbid suits.
I would bid 2H with the hand you
要保证三门都有挡张，关键是庄位好，如方块拿着K 10 X,K J X, Q 10 X等，对于2NT是否逼叫的问题，牵涉到对反低花加叫的要求，牌手可以自己决定。第三，PASS并不是表示方块没有挡张，而是一种逼叫性PASS，通常是均型，方块套不适于做庄或者是牌力较强不愿意叫2NT(可能是不逼叫的)。
Cozofu：the problem is that you
usually don't have major suit fit. When you say you bid 2H/S to
show unbalanced hand, you usually have shortness somewhere,so you
can often splinter your shortness over 2D. Introducing a
major suit isn't very valuable in my opinion. You usually can gain
at high level competition after you introduce a new suit only when
you have some potential fit in that new suit, but pd's raise
denies a fit in that suit. He usually denies an unbalanced hand as
well, because he can splinter at 3 level with shortness if he has
one, so you usually know he has about 2-3 cards in the suit. Also,
your side has found the fit and you know your side has more HCP,
so the basic concern is that whether 3NT is a reasonable contract.
Without 2D, you would usually show the position of your stopper,
so we still can pretty much play the same way even after opps
overcall 2D. The only draw back is that sometimes 3NT may be wrong
sided if you have something like this: SAxx HKx DAxx CQxxxx,
because once a while partner may have DQx. however, even if you
passed 2D, you may not get your pd to play 3NT.Because with DQx,
he might not be able to bid 3NT. So positional issue isn't really
a big concern here. There is also a way to solve this problem: if
you think pd should declare, you can sometimes pass 2D, then
cuebid 3D over pd's bid, which asks for half stopper, so this
sequence would garantee pd to declare 3NT. However, you still may
backfire sometimes, because sometimes pd may not have half stopper
in D, but you still have 9 easy tricks in 3NT. Anyway, sometimes,
it's really a guessing game.
Also, I am testing a 4 card major opening system with 1NT
semiforcing and 2/1 game forcing, 1NT: 14-16 HCP. It works
well. I personally prefer a 4 card major opening system.