Discarding from Length vs Shortness

As declarer runs a long suit, defenders are repeatedly forced to discard. Choosing the wrong discard will hand declarer the contract. The rule is: Discard from shortness, and maintain length parity with dummy's threats.

Why parity works

If dummy holds a 4-card suit headed by the King (K-4-3-2), and you hold four small cards (8-7-6-5), your small cards are "guards." If declarer plays the Ace, King, and Queen, dummy's last card (the 2) will be a master winner IF you threw away one of your guards.

By keeping all four of your small cards, you match dummy's length (parity). When declarer plays the fourth round, you win the trick with your 8! You must throw away cards from suits where dummy is short, as you cannot be squeezed there.

A worked example: Protecting the spot cards

Declarer is cashing 5 Clubs in 3NT.

Dummy:

♠ K Q 5 4

♥ 3 2

You (East):

♠ 10 9 8 7

♥ K J 4

Caption: As declarer plays Clubs, you must discard. Do NOT discard a Spade! You have 4 Spades, matching dummy's 4 Spades. If you throw a Spade, dummy's 4th Spade will become a winner. Discard your Hearts, because dummy only has two Hearts and poses no length threat there.

Four common mistakes

• Throwing small cards from a 4-card suit because they "aren't winners" (they are vital guards!).
• Discarding from partner's established long suit.
• Failing to watch partner's discards to see which suits they are guarding.
• Breaking parity with dummy's visible long suit.

When the rule does not apply

If partner explicitly signals that they hold the master stoppers in a specific suit, you are relieved of your guarding duties. You can safely discard from that suit and protect something else.

Key takeaways

• Keep equal length (parity) with dummy's long suits.
• Discard from suits where dummy is short.
• Small spot cards (8s and 9s) are vital guards.
• Watch partner's signals to share the guarding burden.