Slam Bidding Mistakes

Slam bidding separates good pairs from great pairs. The difference between making 6♠ (1430) and stopping in 4♠ (680) is 750 points—13 IMPs. But bidding a failing slam when you should stop in game costs even more. Here’s how to avoid the most expensive mistakes.

Missing Cold Slams: The “We Don’t Have Enough Points” Fallacy

The Problem: Counting only HCP and missing shape, fit, and controls.

Example Auction:

West    East
1♠      3♠ (limit raise)
???

West’s Hand:

♠ A K Q 10 7 3
♥ A 5
♦ K Q 8
♣ 7 2

East’s Hand:

♠ J 9 6 2
♥ 7 4
♦ A J 9 5
♣ A 8 3

West has 17 HCP, East has 11 HCP. That’s only 28—many players stop at 4♠. But count the hand properly:

Six-card trump suit (West) + 4-card support (East) = 10 trumps
First-round control in three suits (two aces in each hand)
Diamond fit (KQ opposite AJ)
West’s singleton club

6♠ is cold: lose one club, make twelve tricks. But if you count “only 28 HCP,” you’ll never bid it.

What to Do Instead: When you have a massive trump fit (9+ cards), prime cards (aces, kings, queens in your suits), and shortness, stop counting points. Start thinking about tricks and controls. West should make a slam try over 3♠ (4♣ or 4♦ control bid, or 4NT Blackwood). East has perfect cards and accepts.

Bidding Slams Off Two Aces

The Problem: Using Blackwood when you shouldn’t.

Example Auction:

West    East
1♥      2NT (Jacoby, game-forcing heart raise)
???

West’s Hand:

♠ 6
♥ K Q J 10 7 3
♦ A K 8 5
♣ K 4

West has 15 HCP, a six-card suit, a singleton, and great controls. East showed a game-forcing heart raise. West gets excited and bids 4NT (Blackwood).

East responds 5♦ (one ace). West bids 6♥.

East’s Hand:

♠ A 8 5 2
♥ A 9 6 4
♦ 7 2
♣ Q J 10

6♥ goes down one: they lose a spade and a diamond immediately. The problem? West bid Blackwood with two quick diamond losers. When East showed only one ace, West should have known there were two cashing aces against them.

What to Do Instead: Don’t use Blackwood when you have a weak suit with fast losers. Instead, control-bid: West should bid 3♠ (showing the singleton and a good hand) or 4♣ (control bid). East will bid 4♦ with a diamond control or sign off in 4♥ without one. Now West can judge whether to bid slam.

The “32 Points = Slam” Myth

The Problem: Bidding slam on pure high-card count without considering controls or fit quality.

Example Auction:

West    East
1NT (15-17)    ???

East’s Hand:

♠ K Q J
♥ K Q J
♦ K Q J 10
♣ K 10 9

East has 18 HCP. Partner has 15-17. That’s 33-35 combined. Many players just blast 6NT.

West’s Hand:

♠ A 10 8 6
♥ A 9 6
♦ 8 5
♣ A Q 8 3

6NT is down immediately: lose two diamond tricks off the top. The problem? All those KQJs look pretty, but there are only three aces between the two hands. You’re missing the diamond ace, and there’s no way to avoid losing two tricks.

What to Do Instead: Count aces and kings, not just points. With 33+ HCP, investigate slam, but use quantitative methods (raise to 4NT asking partner to bid 6NT with maximum) or Gerber (4♣ asking for aces). Don’t just blast.

Blackwood With a Void

The Problem: Using standard Blackwood when you have a void, getting a useless answer.

Example Auction:

West    East
1♠      3♠
4NT     5♥ (two aces)
???

West’s Hand:

♠ A K 10 7 6 3
♥ —
♦ A K Q 8 5
♣ 9 4

West has a void in hearts and two aces. Partner shows two aces. But which two? If partner has ♥A and ♣A, you’re missing the diamond ace and might lose a club. If partner has ♦A and ♣A, you’re golden—the ♥A is worthless to them anyway.

Standard Blackwood can’t distinguish. West is stuck.

What to Do Instead: With a void, use control-bidding or Roman Key Card Blackwood (which includes the trump king in responses). Or bid 5NT (pick-a-slam) and let partner choose. Better yet, control-bid first: 4♥ shows heart control (here, a void), 4♦ shows diamond control. Let partner cooperate.

Not Using Blackwood When You Should

The Problem: Wandering around with control bids when simple Blackwood would work.

Example Auction:

West    East
1♠      2♣ (game-forcing)
2♠      3♠
4♣      4♦
4♥      ???

East’s Hand:

♠ K Q 8 6
♥ A 5
♦ K Q 7
♣ A 10 7 3

Both players are control-bidding. East has shown controls in clubs, diamonds, and hearts. West has agreed to spades and shown controls all around. What’s East supposed to do now? Bid 5♣? 4♠?

This is silly. Both players have shown strong hands with controls. Just bid 4NT (Blackwood)!

What to Do Instead: Use Blackwood when:

You have a known fit
You have no worthless doubletons
You just need to know about aces/key cards

Don’t make slam bidding harder than it is.

The “Weak Freak” Slam

The Problem: Pushing for slam with distribution but no controls.

Example Auction:

West    East
2♣ (strong)    2♦ (waiting)
2♠      3♠
???

West’s Hand:

♠ A K Q 10 8 7 6
♥ K 10 9 8 7
♦ —
♣ 5

West opened 2♣, rebid spades, and East raised. West has eleven cards in two suits (6-5) and a void! This looks like a slam hand—there are so many tricks!

But West only has 12 HCP. And two major kings are not “controls”—they’re likely to produce tricks, but they don’t control suits. If East has:

♠ J 9 3 2
♥ A 3
♦ K 8 7 4
♣ K Q 6

6♠ is down: lose the ♥A and two clubs immediately (or one club and one diamond if you ruff one). You don’t have enough controls—just shape.

What to Do Instead: With distributional hands, make a slam try (4NT or control-bid), but don’t force slam without first-round controls. Let partner show key cards. Here, East has one key card (♥A), and West has two (♠AK). That’s only three key cards—missing two aces equivalent. Sign off in 5♠ or pass 5♥.

Forgetting About Trump Quality

The Problem: Bidding slam with a weak trump suit.

Example Auction:

West    East
1♥      3♥ (limit raise)
4NT     5♦ (one key card)
6♥      Pass

West’s Hand:

♠ A 5
♥ K 10 8 7 3
♦ A K Q
♣ K 10 8

East’s Hand:

♠ K 7 4
♥ Q 9 6 2
♦ J 10 5
♣ A 9 3

West counted 20 HCP, East has 11, partner showed one key card (♥A), so West bid 6♥.

6♥ is terrible: trumps split 4-1, and West loses a spade and a trump. Even if trumps split 3-2, you’re missing ♥AQJ—you have four trump losers potentially!

What to Do Instead: When your trump suit is weak (no ace, no queen, or missing three of the top five honors), be cautious about slam. Consider asking about trump quality (the Queen ask: 5NT after Blackwood). Or just stop in game—620 is better than -50.

The Undiscussed Sequence

The Problem: Making a slam try partner doesn’t recognize.

Example Auction:

West    East
1NT     3♠
???

What does 3♠ mean? Some pairs play it as a weak hand with six spades (to play). Others play it as game-forcing with slam interest. Others play it as invitational.

If West and East have different understandings, disaster follows.

What to Do Instead: Discuss your slam methods with partner BEFORE the game:

After 1NT, how do you show slam interest? (Jacoby transfer then jump? Gerber? Quantitative 4NT?)
What is 4NT after Jacoby 2NT?
Do you play control bids or just Blackwood?
What is Roman Key Card Blackwood?

Write it down. The best slam bidders have clear, simple agreements.

Bidding Grand Slams Without Counting Tricks

The Problem: Bidding seven based on key cards alone.

Example Auction:

West    East
1♠      2♣ (game-forcing)
2♠      4NT (Roman Key Card)
5♥ (2 + Q)    ???

East holds:

♠ K Q 8 6
♥ A K
♦ A K Q J
♣ A 10 5

Partner showed two key cards plus the trump queen. That’s ♠A and one other key card (probably ♥K or ♣K). East has all the other aces and the ♦KQJ. Should East bid 7♠?

NO! Count tricks: Partner has ♠AJxxx and maybe ♥K. That’s five spade tricks and two hearts. East has diamonds for four tricks and ♣A for one. That’s twelve tricks, not thirteen. You’re missing a long trump or a long club.

What to Do Instead: Grand slams require 13 tricks, not just all the key cards. After confirming key cards, ask yourself: Where is the 13th trick coming from? If you can’t answer, stop in six.

Bottom Line

Slam bidding mistakes fall into four categories:

Missing slams (counting only points, ignoring fit and controls)
Bidding bad slams (using Blackwood wrong, ignoring fast losers, weak trumps)
Method confusion (Blackwood with voids, not discussing sequences)
Grand slam optimism (bidding seven without 13 tricks)

The fix: Learn control-bidding basics. Understand when to use Blackwood and when not to. Count aces and tricks, not just points. And most importantly, discuss slam methods with your partner. A simple agreement beats a complex system every time.

Slams are exciting, but the best slam bidders know when NOT to bid them. Stay in game when you should, and you’ll win more than the pair that bids every marginal slam.