I’m unclear as to the best matchpoint strategy about inviting game facing a no-trump opener. I think I understand that it is right to have full values to invite when balanced – but what about with a shapely hand? Recently after transferring to spades with ♠ A-6-5-4-2, ♥ 10-3 ♦ K-10-9-3-2, ♣ 2, I decided it was best to pass when my partner did not break the transfer. The best game for us was five diamonds when my partner had a doubleton spade king, but even the spade game came home today.

Patrick Thistle, Schaumburg, Ill.

My general approach here is to transfer to spades and bid two no-trump with balanced hands, but to make a light invitation with five spades in an unbalanced hand via Stayman then two spades over a red suit. That might not help here, I admit but at least I can differentiate my invitations.

I know you are not an especial fan of Bergen Raises, but if playing semi-forcing no-trump would you consider using a direct jump to three clubs as an invitational three-card spade raise? A three diamond call could be four trump, or some other kind of invitational hand.

Thoroughly Modern Mindy, Elmira, N.Y.

For me simplest is best. I don’t mind playing forcing or semi-forcing no-trump, and even if using the latter I can put balanced invitations with three trump through this response. If I end up in one no-trump facing a minimum balanced hand, it might be our last (or best) plus score. Three level jumps are thus natural and invitational.

You recently suggested that a reader might raise his partner’s opening one spade bid to three no-trump as a good raise to four spades. Might not opener pass expecting a balanced hand without spade support?

Jimbo in Limbo, Kenosha, Wis.

I was suggesting using the three no-trump call as purely artificial, not a suggestion of a place to play. It can be used to show a spade raise with less than the minimum for a Jacoby two no-trump response, but still with enough shape to want to play game. Shading the Jacoby response can lead to problems when opener tries for slam expecting more values opposite. The three no-trump call can either be used as a shapely raise to game or, if you prefer, as a splinter in an unspecified suit instead. If the latter, partner can relay to find out if interested.

When bidding in sandwich seat I’m often confused about whether to overcall, double or bid one no-trump if I hold a strong hand. Recently with ♠ K-9-2, ♥ A-J, ♦ A-J-9-6-4, ♣ K-10-3 I was not even sure if I should come into my opponents’ auction at all, after hearing one club on my left, and one heart to my right. What would you bid?

Duke of Earl, Charlottesville, Va.

I would bid here, but the choice between overcalling, doubling, and bidding one no-trump is indeed a close one. Your high-cards make it relatively safe to double, a little less safe to bid one no-trump or two diamonds, since you can more easily get doubled for penalty. I suppose my extra values make it right to double now.

Are there any major contributions to bidding theory in the last 20 years – or has everything that could be found out about the game already been published?

Novelty Hunter, Grand Forks, N.D.

The modern tendency at expert level to use transfer responses to a natural but potentially short club is undeniably interesting. I’m also particularly taken with the idea that the call of two no-trump can be used in competition as either a raise or a purely competitive call (to distinguish it from invitational hands). See http://webpages.mcgill.ca/staff/group3/gberns/world/new%20bridge%20site/myweb4/Articles/Competitive%20Bidding/Good%20Bad%202NT.pdf