This bidding section is meant for beginners and those players who like to keep it simple. Test your knowledge.

Solution

South 1 bids 2♥. He shows suit preference for hearts, but not per se three hearts, since this is not a support bid! Very often he will have only two hearts (if 1♥ showed a five-card suit already, this is almost certain; South's 2♥ bid then virtually denies three-card support). This is one of the three weak bids (showing 6-9 points) he can make.
The other two are:
- Pass, with which South shows suit preference for diamonds (he doesn't do so here, since a 5-2 trump fit — hearts — is usually superior to a 4-3 fit — diamonds).
- 2♠, with which South shows a six-card spade suit (or a very good five-card suit).
Though he has a guard in the unbid suit, clubs, South 1 should not make the mistake of bidding 2NT (read below why this is a mistake).

South 2 bids 2NT. He has a guard in the unbid suit, clubs, and no fit in North's major suit. Furthermore he has 11 HCP, the right amount for the invitational 2NT bid. Opposite an opened (in one in a suit) hand that has not shown extra strength, 2NT by responder always shows about 11 HCP. The reason is that the bid is invitational: opener will pass with a minimum (12-13, or a bad 14 count) and bid on with more.

Realise the logic of the above. Suppose South 1 would bid 2NT (unfortunately many players would):
- If North now passes, showing a minimum (12-13/14), South will be defeated in 2NT since NS have only 19-20/21 HCP between them).
- If North has 15-16 HCP, 2NT will stand a fair chance. But South will not play that contract then, since North will bid game. Another sad result, therefore. So South will be defeated in either 2NT or 3NT (depending on North's strength)...
Only if North has a good 17 count, or 18 HCP, will South stand a chance in 3(!)NT after having bid 2NT but if North had this hand he would bid on over South's sign-off in 2♥.
There is another way to look at this: if South 1 (7 HCP) and South 2 (11 HCP) both bid 2NT, North will not know what to do with 14-16 HCP.

Once more: after an opening of one in a suit and a response in a suit, 2NT, whoever bids it, is usually invitational to 3NT. So if opener can still have a minimum, responder shows 10-11 HCP when bidding 2NT.
If opener has shown 16-19 HCP (by way of a reverse bid), 2NT by responder shows 7-8 HCP: thereafter opener will pass with a minimum of 16-17 HCP and bid on with a maximum of 18-19).