When my partner responds five diamonds to Key-card Blackwood, how do I know whether he is showing one ace or the trump king? If I held two aces, I would need this information to know whether to bid slam.

Year Dot, Springfield, Mass.

You never want to play slam if you are missing two aces, but missing one ace and the trump king is almost as bad. While the auction can occasionally indicate that the finesse is favored to succeed, you will rarely know that for sure. Essentially, the trump king is as good as an ace, and you do not need to differentiate. Indeed, even when you have a nine-card fit, possession of the trump queen will often be critical.

With a hand such as ♠ A-J-4, ♥ A-Q-9, ♦ J-9-5, ♣ 10-8-7-2, is there ever a seat or vulnerability in which you would pass, as opposed to opening the bidding? When I held this hand vulnerable in second seat, I thought the flat shape and weak long suit superseded the two aces. The traveling score-slip at our duplicate suggested that I was the only one who passed.

Taciturn Tim, Manhattan Beach, Calif.

Flat 12-counts do not have to be opened — particularly when it requires you to bid a bad suit, as here. Doing so may get partner off to the wrong lead if you end up on defense. With two four-card suits or a five-carder, I would almost never pass, however.

Suppose you are 5-5 in a major and a minor and hear your righthand opponent open the minor, which could be two cards. Is it best to wait for one round, perhaps hoping to hear partner balance with a take-out double? Or is it better to ignore the minor and bid the major?

Still Waiting, Albuquerque, N.M.

When you have length in your right-hand opponent’s bid minor, whether the opening guarantees length or not, you should overcall. You may never get a second chance if you do not act at once. With any luck, you may get a chance to bid the second suit at your next turn if you haven’t already found a fit.

In fourth chair, you are dealt ♠ A-10-8-2, ♥ J-9-4, ♦ K-J-7-6, ♣ Q-10, and you hear a weak two spades on your left, double by partner and three spades on your right. You bid three no-trump, over which partner bids four hearts. Should you bid on?

Pre-empts Work, Charleston, S.C.

While you have a decent hand, you implied opening values when you contracted for game. You are close to cue-bidding four spades, but I’d pass, primarily because with anything like a slam-drive, partner might have done more himself. I’d expect him to have at least five hearts and a spade void, but not necessarily a great hand.

Recently, I held ♠ A-J-7-4-3, ♥ 6-4, ♦ K-Q, ♣ J-10-8-7. I responded one spade to partner’s one-club opening, and my partner now jumped to four spades. What should I expect, and what should I do next?

Lots in Reserve, Newport News, Va.

A jump to four spades suggests a relatively balanced hand with more than a strong no-trump. (Partner could make a splinter raise to four hearts or four diamonds, or could jump to four clubs to show a 6-4 hand type). Your hand has real slam potential, but I’m not sure it is worth more than a cue-bid of five diamonds and reverting to five spades over a five-heart response.