Active vs Passive Defense

The hardest decision in defense isn’t what suit to lead. It’s whether to lead at all.

Sometimes you need to attack now, right now, before declarer takes your tricks away. Other times you should sit quiet, force declarer to break suits themselves, and wait for your tricks to come.

Get it wrong and you’ll blow cold contracts or let laydown games make. Get it right and you’ll beat contracts that looked unbeatable.

The Core Question

Every defensive decision comes down to this: Does declarer have time, or do we?

If declarer has time to develop tricks, you need to attack (active defense). If you have time to wait for tricks, you should wait (passive defense).

Sounds simple. It’s not.

When to Attack (Active Defense)

Declarer Has a Long Suit

Dummy hits with six diamonds to the K-Q-J. Declarer has the ace. Once those diamonds run, your side tricks disappear. You need to cash out or establish tricks before declarer gets in.

Example Hand #1: Attack or Lose

Contract: 3NT by South

Dummy (North)
♠ 7 4
♥ 9 6 3
♦ K Q J 10 8 2
♣ A 5

You (West)
♠ K Q J 10 2
♥ A 8 2
♦ 7 5
♣ 9 7 3

Bidding: 1NT - 3NT

Partner leads ♣6, dummy’s ace wins, declarer follows with the 4.

Declarer immediately attacks diamonds. You duck one round, win the second with partner showing out.

What now?

Declarer has five diamond tricks ready to cash plus the ♣A. That’s six. They need three more. You can see they’re not coming from hearts (dummy has rags). They’ll come from spades or clubs.

This is active defense territory. You need to cash four tricks before declarer cashes nine. Lead the ♠K now. If partner has the ace or declarer has A-x, you’ll take four spade tricks first. If declarer has A-x-x, you’re probably going down anyway.

Sitting passively? Fatal. Declarer will knock out your ♥A and score up nine tricks.

Declarer Can Pitch Losers

If dummy has a long suit and declarer has a short suit, you’re racing against discards.

Example Hand #2: The Discard Race

Contract: 4♠ by South

Dummy (North)
♠ K 9 3
♥ 8 2
♦ A K Q J 10
♣ 7 6 3

You (East)
♠ 6 4
♥ K Q 10 5
♦ 9 6 4
♣ A K 8 2

Bidding: 1♠ - 2♦ - 2♠ - 4♠

Partner leads ♥3, your queen wins, declarer follows with the 7.

Dummy has five diamond winners. Declarer will pitch heart losers and club losers on those diamonds. You need to grab your tricks RIGHT NOW.

Cash ♥K (declarer follows with the 9). Now shift to the ♣A, then ♣K. That’s four tricks if partner has a club honor or a heart trick.

If you woodenly continue hearts, declarer wins the ace, draws trumps, and pitches two clubs on the diamonds. You get one club instead of two. Down one becomes making four.

When to Wait (Passive Defense)

Declarer Has Guess

If declarer has to guess where the queen is, don’t solve it for them.

Example Hand #3: Let Them Guess

Contract: 3NT by South

Dummy (North)
♠ A 10 4
♥ K 6 3
♦ Q J 5
♣ K Q 10 2

You (West)
♠ K J 6 3
♥ 10 8 7 2
♦ 10 6 3
♣ 7 4

Bidding: 1NT - 3NT

Partner leads ♠5 (fourth best), dummy plays the 10, you win the jack, declarer follows with the 2.

What do you return?

Not spades. Declarer has Q-x (partner led fourth best from a 4-card suit, so declarer has exactly 2). If you continue spades, you’re setting up dummy’s ♠A-10.

Not hearts. You’d be leading from 10-x-x-x into dummy’s K-x-x. That’s gift-wrapping a trick.

Not diamonds. Same problem.

Try a club. Dummy has K-Q-10-2. Declarer will have to guess whether to finesse or play for the drop. Don’t lead from your club holding if you have one, but a passive club exit makes declarer do the work.

Actually, best is probably a diamond. Force declarer to commit in every suit. This is passive defense: Don’t give anything away. Make them earn it.

No Entry Problems

If declarer can’t get back and forth between hands easily, passive defense wins. Every time you lead, you’re potentially solving an entry problem for them.

Example Hand #4: Cut Their Entries

Contract: 3NT by South

Dummy (North)
♠ 9 6 4
♥ 5 3
♦ A K Q J 10
♣ 8 7 2

You (East)
♠ K J 8 3
♥ Q J 10 2
♦ 8 3
♣ K 10 5

Partner leads ♠2

Dummy has five diamond tricks but no entry except the diamonds themselves. If declarer has the ♠A-Q and ♣A-Q, they’re cold for nine tricks.

But watch what happens if you defend passively. Win the ♠K, return a spade. Declarer wins, cashes diamonds. You pitch clubs. When they exit a club, you win and exit a heart.

Declarer never gets to use all those diamond tricks because they can’t get back to dummy. They might have to finesse clubs or hearts from hand without entries.

Passive defense makes declarer work for every entry. Active defense (leading hearts or clubs) solves their problems.

The Recognition Framework

Ask yourself three questions:

Question 1: Can declarer run a long suit?

YES → Active (attack before they cash out)
NO → Consider Question 2

Question 2: Can declarer pitch losers?

YES → Active (cash your tricks before they vanish)
NO → Consider Question 3

Question 3: Do we have declarer’s tricks?

YES → Passive (wait, don’t give anything away)
NO → Active (we need to create tricks somehow)

Advanced: Reading Declarer’s Play Tempo

Declarer tells you which defense to choose by how they play.

Fast play from declarer = They have tricks, they’re running

This is your cue to attack. If declarer bangs down the ♠A-K quickly, they’re not worried. They have tricks to cash. You better find yours fast.

Slow play from declarer = They’re stuck, they have problems

This is your cue to sit back. If declarer thinks a long time before leading from dummy, they’re trying to solve a problem. Don’t solve it for them. Exit safely and make them guess.

Example Hand #5: Reading the Tempo

Contract: 4♥ by South

Dummy (North)
♠ K Q 3
♥ K 10 8 4
♦ 7 6 2
♣ A 8 3

You (West)
♠ 9 6 4 2
♥ 5
♦ K Q 10 3
♣ J 10 6 2

Bidding: 1♥ - 4♥

You lead ♦K, partner plays the 8, declarer the 4. You continue ♦Q, partner plays the 9, declarer wins the ace.

Declarer thinks. Long time. Finally leads a trump to dummy’s king (your partner follows with the 2, you pitch a spade).

Declarer thinks again. Leads the ♠K from dummy.

Should you ruff?

No! Declarer is in trouble. They’re trying to pitch a diamond loser on spades. But they haven’t drawn all the trumps (they’d need three rounds, they’ve only taken one). If you ruff in, you’re ruffing a loser. Declarer will overruff, draw trumps, and claim.

Instead, pitch a club. Make declarer solve their own problems. Maybe they have a club loser, maybe a diamond loser. Let them figure it out. That’s passive defense.

If declarer had banged down trumps quickly and started running spades, different story. They’d have the trumps under control. Then you’d need active defense (maybe a club shift to partner’s queen).

Special Case: Suit Contracts

Trump contracts lean passive. Here’s why.

In notrump, every side suit matters. In a suit contract, declarer has trump. If you lead a side suit and they have nothing, they just ruff.

The classic mistake: Leading from K-x-x in a suit nobody bid. You’re giving declarer a free finesse or a ruffing opportunity.

Default in trump contracts: Passive unless you have a clear reason to attack.

Clear reasons to attack:

Dummy has a long suit to pitch on
Declarer showed a two-suiter and you need to stop ruffs
You need to promote a trump trick (uppercut, etc.)

Otherwise? Exit safe. Make declarer break the suits.

The One Exception: Opening Lead

The opening lead is different. You can’t be purely passive on lead (you have to lead something). So on opening lead, prefer active.

Lead from your longest suit, or partner’s suit. Try to establish tricks. Don’t worry too much about giving away a trick if the alternative is letting declarer run.

After the opening lead, that’s when the active/passive decision really kicks in.

Common Mistakes

Being active when declarer has all day

Declarer opened 1NT, dummy has balanced junk, no long suit. Declarer needs to work for nine tricks. You lead from K-J-x into dummy’s A-10-x. You just gave away the contract.

Being passive when dummy has six tricks ready to run

Declarer opened 1♦, dummy has ♦A-K-Q-J-10-9. You won the first trump trick. Partner has the ♠A. You exit a safe trump. Declarer draws trump, runs diamonds, pitches all their spade losers. Oops.

Practice Recognition

Next ten hands you defend, ask on trick two: “Active or passive?”

Don’t just guess. Work through the framework:

Long suit in dummy? (active)
Pitching position? (active)
Declarer has problems? (passive)

You’ll get it wrong sometimes. That’s fine. The key is having a reason, not just a guess.

After a few sessions, it’ll click. You’ll see dummy and know instantly: attack or wait. And your defensive results will jump.