How to Run a Suit to Pressure Defenders

When you are in a No-Trump or suit contract and realise you are exactly one trick short of making your goal, one of the most effective practical techniques is simply to Run a Long Suit. This means cashing all the winning cards in your longest established suit back-to-back, without stopping to play other suits. While this isn't a mathematically perfect "squeeze," it puts immense psychological and structural pressure on the defenders, forcing them to discard cards from their hands.

Why running a suit works

Defenders cannot see each other's cards. When you cash five rounds of Clubs, the defenders must discard five cards. Often, they do not know which suits their partner is protecting.

Under this barrage of discards, a defender might panic and throw away a guard (like the ♠10 when you hold the ♠J) or unguard an honour (throwing a small Heart away from the ♥K). When they make this mistake, your previously losing card becomes a winner!

A worked example: Forcing a discard error

You are in 3NT. You have 8 top tricks: 5 Clubs, 2 Diamonds, and 1 Heart. You need one more trick. You hold ♠A-J-2, and the defenders hold the ♠K-Q-10.

The Play:

Instead of guessing what to do in Spades, you simply cash your 5 Club winners immediately.

Caption: As you play your 5 Clubs, West is forced to discard. West holds the ♠K-Q and the ♥K. Afraid of letting you win a Heart trick, West throws away a Spade. East, holding the ♠10, assumes West is protecting Spades and also throws a Spade to keep their Diamonds. Suddenly, the defenders have thrown away their Spade guards! Your ♠J is now a winning trick.

Four common mistakes

• Cashing all your winners but discarding the wrong cards from dummy, ruining your own chances.
• Stopping in the middle of running the suit to take a finesse (run the whole suit to maximize pressure before taking the finesse!).
• Not paying close attention to what the defenders are discarding.
• Running a suit when you have a perfectly safe mathematical line of play available.

When the rule does not apply

If you have a guaranteed 100% line of play (like a solid finesse or an established side suit), do not rely on the opponents making a mistake. Running a suit is a technique to use when your legitimate chances of making the contract look bleak.

Key takeaways

• Cash a long string of winners back-to-back.
• Forces the defenders to make difficult discard decisions.
• Often results in defenders accidentally throwing away winning cards or guards.
• Keep track of the defenders' discards to spot their mistakes.