Third and Fifth Leads
Third and fifth opening leads were originally designed for four or five card suits, respectively. From a four card suit, the third lowest card is led. From a five card suit (or longer), the fifth lowest card is led.
Examples:
- K953 - lead the 5.
- Q9762 - lead the 2.
- J86542 - lead the 4.
Alternatively, many players use third and fifth leads from an even or odd number of cards, respectively. The opening leader leads the third highest card from an even number of cards in a suit, and the fifth highest card from an odd number.
Examples:
- K953 - lead the 5.
- Q9762 - lead the 2.
- J86542 - lead the 6.
The difference between the original practice is subtle - from a six card suit, the third highest card is led instead of the fifth highest card.
The benefit of third and fifth leads is that they help partner gauge your suit length. Playing standard leads, the 2 would be led from both K92 and K972. Playing third and fifth however, the lead of a 2 always indicates a three or five card suit. It's easier for partner to try guess whether you hold three or five cards in the suit, rather than whether you hold three or four.
A disadvantage of third and fifth leads is that the third highest card is sometimes too costly to lead. For example, leading the 9 from KJ92 can easily blow a trick.
Other Considerations
Third and fifth leads are used in conjunction with the Rule of 10 and 12. These mathematical formulas are used by the opening leader's partner to count how many higher cards declarer has in the suit.
