A: with K9742 one should lead the 4.

B: with KQ87 one should lead the 7.

4^th best used again both suit and NT contracts.

Rule of 11

One of the reasons 4^th best is so popular, is the rule eleven. If one take the value of the card lead and subtracts it from 11, which will tell them how many higher-ranking cards are remaining.

Applying this to example A, 11-4=7. So there are seven cards high then the four that my partner doesn't have. Let's say the dummy has T3, and I hold the J5. I know the declarer has 4 cards higher then the four.

In example B, assuming the same holdings for dummy and myself, I know declarer on has two cards higher then the 7. Additional inferences would allow me to figure out what my partner's possible holdings are.

Quick Rules

Always lead the top of two

K from AK combinations

Other touching honors, if 3 always lead top honor, if 2 and suit contract lead top, if NT lead 4^th best

Lead top of broken sequences

3 cards non-touching honors, lead third

4 cards non-touching honors, lead 4^th

What to lead?

KQJ

T98

QT

KQ952

K62

KT98

Visit this great sight for more.

http://www.prairienet.org/bridge/leads.htm

Some Basic Defensive Problems

AKQJ9

K53

AT3

K6

T72

North opens 1S-p-1N-p; 3NT-p-p-p

Partner leads the 7 of hearts, plan your play?

A852

T64

JT73

Q9

QJT7

J983

South opens 1D-1S; 2NT-3NT

Partner Lead the 7 of clubs

65

A8

KT743

QJT2

JT973

South opens 1NT-3NT

Partner leads the 7 of hearts