Fourth Highest Leads

When leading a low card from a long suit it's normal to lead your fourth highest. Doing so will help partner know the length of your suit.

In this first example, North leads the ♥2 against West's 3NT contract. North has no cards lower than the 2 so he must have started with exactly four hearts.

North started with four hearts!

This time, North leads the ♥6 against West's 3NT contract. You can't see the ♥4 yet so you can't be sure about North's heart length. Once you see the ♥4 you'll know whether North started with four or five hearts.

Who has the ♥4?

You can also use the rule of 11 after a fourth highest lead to quickly calculate where the missing honours are located.