Slam Bidding in Bridge

The usual guide is 33 combined high-card points for a small slam and 37 for a grand. The arithmetic behind the numbers is plain. If the two hands hold 33, the opponents have at most 7, which is not enough for two aces. At 37 they have at most 3, not even one ace.

Those figures are for balanced hands, where tricks come only from high cards and long suits. Some teachers quote 32 or 33, and the difference matters less than people think, because the count is only the starting point. Once the hands have a trump fit, shape starts to take tricks that points cannot see. Two hands with 28 points, a nine-card fit and a singleton opposite small cards often make twelve tricks, while two flat 33-point hands sometimes need a finesse. The scores in the table come from the scoring rules: the small slam adds 500 not vulnerable and 750 vulnerable to the game bonus, the grand 1000 and 1500.

Experienced players do not wait to reach 33. They notice the moments when partner's bid makes their own hand better than it looked a round ago, and they start asking. These are the signs worth reacting to:

• A big fit. Nine or more trumps between you, or a second fit in a side suit. Each extra trump is roughly an extra trick.
• Shortness opposite small cards. A singleton or void facing three small cards loses nothing, and every honor you hold is working in the other suits. The losing trick count measures this better than points do.
• A source of tricks. A long suit that runs, or will run after one round of ruffing, turns a 30-point hand into twelve tricks.
• Controls. Aces, kings, voids and singletons. Two hands can hold 33 points and still be missing the ace and king of the same suit, and hand evaluation counts controls for that reason.
• A strong bid from partner. A jump shift, a jump rebid, a strong 2♣ opening or a jump to game in a new suit says partner has more than you might have assumed. Add your points to the top of partner's range and see where you land.

The reverse signs count just as much. Queens and jacks in partner's short suit, a flat 4-3-3-3 hand, and honors with no length to back them up all make a slam less likely than the point count says.

The tools fall into two groups. The first group describes the hands and helps judge whether twelve tricks are there. The second group asks how many aces or key cards the partnership holds, which says nothing about fit. Use them in that order. A key card ask made before the fit is known gets an exact answer to the wrong question.

A typical suit slam uses three of these in turn. A raise such as Jacoby 2NT or a splinter sets the trump suit and shows shape. Cue bids then check that no side suit is open. Only then does the captain ask for key cards with 4NT, and with the answer in hand places the contract. Many good slams need only one or two of those steps, but the order does not change.

Blackwood and RKCB count aces. They cannot tell you whether the opponents can cash the ace and king of a suit where you hold two small cards. That is a control question, and the tools for it are bids that describe your hand below game.

A splinter shows shortness at once, so partner can judge how many of their points are working. A control cue bid shows an ace or king (or a void or singleton in most partnerships) in a side suit, and skipping a suit denies a control there. Cue bids go up the line, cheapest first, and a return to the trump suit is a sign-off. If both of you have bypassed a suit, nobody holds a control in it, and the right contract is five of the trump suit at most.

One habit helps more than any convention. Before you bid 4NT, look at each side suit in your hand and ask what happens if partner has two small cards there too. If that leaves two quick losers, cue-bid first.

Once the fit is known and every suit is controlled, 4NT asks how many aces or key cards partner holds. Plain Blackwood answers with aces only. Roman Key Card Blackwood counts the trump king as a fifth ace and finds the trump queen, and most tournament pairs play it in the 1430 form. The rule for the captain is the same in both. Missing two aces or two key cards, sign off at the five level. Missing one, bid the small slam. Missing none, think about a grand.

Three hands should not use 4NT at all. A hand with a void gets no help, because partner counts an ace in your void as if it took a trick, so use Exclusion Blackwood or cue bids. A hand with two small cards in an unbid suit needs a cue bid first. And when clubs are trumps, a two-ace answer can carry the auction past five of the trump suit. Ask only if every answer leaves you a sensible contract.

Over a natural 1NT or 2NT, 4NT is quantitative, so the ace ask moves down to Gerber, the jump to 4♣. If the opponents bid over your 4NT, DOPI and ROPI let partner still answer.

Balanced hands opposite a notrump opening are where point counting works best, because there is no fit or shape to complicate it. Add your points to partner's range and bid by the total. Opposite a 15 to 17 point 1NT, most pairs play the responses below.

Over a 20 to 21 point 2NT the same idea applies a level higher. About 11 or 12 points invites with 4NT, and 13 to 15 bids 6NT directly. Opener answering a quantitative 4NT passes with the bottom of the range and bids 6NT with the top. Holding the middle, a good five-card suit or a fistful of tens and nines tips the decision toward slam. Some partnerships let opener show a four-card suit on the way to 6NT, which can find a 4-4 fit that makes twelve tricks when notrump makes only eleven. That needs discussion first.

A grand slam needs 13 tricks and no losers at all, so the questions get sharper. All four aces must be present, which is why 5NT after Blackwood or RKCB promises them and asks for kings. The trump suit must have no loser either, and that is the job of the grand slam force.

The grand slam force is a jump to 5NT, not preceded by 4NT, once a trump suit is agreed. Ely Culbertson devised it in 1936 and his wife Josephine wrote it up, which is why some players still call it Josephine. The original rule still works. Partner bids seven of the trump suit holding two of the top three honors, the ace, king and queen, and six without them. Many partnerships now play graded replies at the six level to show one top honor or none, so check which version you play. Use it when the rest of the hand is under control and the only doubt is the top of the trump suit.

The bar for bidding seven is higher than for six. At IMPs a grand slam needs about 56 percent to be worth bidding, against 50 for a small slam (see game and slam odds), because going down in seven throws away a small slam that was cold. A grand that depends on a finesse is a losing bet.

A 28-point slam after a splinter

Count the tricks. Five hearts in the North hand, a club ruff in dummy, three spades and three diamonds make twelve, losing one club. The missing key card is either the ♣A, which only takes the trick North was always going to lose, or the ♥K, in which case South holds the ♣A and the slam rests on the heart finesse. At 28 points a point counter would have stopped in 4♥.

A 33-point slam in notrump

This deal shows what 33 points buys. There are three spades, four diamonds and two clubs once the ♣A is driven out. Add the ♥A and ♥K for eleven, and the twelfth comes from the heart finesse against the queen. A slam on a finesse is about the even chance a small slam needs. Two 4-3-3-3 hands are the worst case for notrump, and with one more five-card suit between them the slam would be close to certain.

• Using 4NT as a slam try. Blackwood and RKCB check aces once you know slam is there. They do not tell you whether the hands fit, and a five-level sign-off is not always safe.
• Asking with a void or two small in an unbid suit. The ace count cannot answer either problem. Cue-bid or use Exclusion Blackwood.
• Counting wasted honors at full value. A king and queen opposite partner's singleton are worth about one trick. Recount after a splinter or a shortness showing bid.
• Reading a quantitative 4NT as Blackwood. Over a natural notrump bid with no suit agreed, 4NT invites 6NT. To ask for aces there, bid 4♣.
• Overruling the captain. The player who asked for aces or key cards places the contract. When the captain signs off, partner passes, whatever their hand looks like.
• Jumping to slam with no exploration. A jump to six gives partner no say. It is fine when you can count twelve tricks, but most hands are better served by a raise that describes them.