In the trump suit

Lacking any of these combinations the fourth highest of the longest suit should be led.
With the hands shown below the mechanics of the card games can be illustrated. South deal and turns up the ♠ 4 to denote trumps. West leads the ♦ 5, and the play is:

West leads the fourth highest of his longest suit, commonly called fourth-best. East wins with the ♦ A. It would be finessing against his partner if he played the ♦ Q. In the event it makes no difference, because East has no better play than to return his partner’s suit, and it is proper to lead the highest from an original holing of three.

South, therefore, wins the second trick, instead of the first, with the ♦ K.

East has no better lead than the ♣ 7. He knows that South hold the ♣ Q, because without it South would No-Trumps have led the ♣ K at the previous poker trick, but it offers a chance of trumping if West can take the lead early in the play.

North has no better lead than the ♣ 9.

East pulls the remaining trumps.

The end position is now as below.

It is North’s lead. North and South have won six tricks, East and West five tricks. North, therefore, leads the ♥ 5. If East wins with ♥ 10 his side will win the odd trick as West will win the last trick with the ♥ 8. North’s only hope is that East will make the mistake of playing the ♥ 4, because then South will win with the ♥ 9 and the last trick with the ♣ 10.

East makes no mistake.

East and West, therefore, have won the implied odd trick and score one point. there is no score for honours as both sides held two.