Immediately after the dummy’s hand has been faced, and before you have told the dummy which card to play on the opening lead, you should analyse the lead and decide what reason your opponent had for making that lead.
If you are missing the ace in the suit led, consider whether the opponent who has led is likely to have the ace.
Example: Declarer ♠972 Dummy ♠K65
You are west and the declarer in 4♥. North leads ♠Q. Who has the ace?
Most players don’t lead a queen when they have the ace. North’s lead looks like the top of a sequence so north will have the jack and south will have the ace.
If you play east’s king on north’s queen, the king will lose to the ace and you will not win any tricks in the suit.
However, if you play low, south might have a singleton ace and be forced to play the ace anyway. Your king will later make a trick.
Alternatively, south may have a doubleton with the ace. If you play low on the first trick, north’s queen will win.
When north leads ♠J to the second trick, play low again and south will have to play their ace. Your king will then make a trick on the third round of the suit.
Here is another situation:
Example: Declarer ♠J7 Dummy ♠K6
You are west and the declarer in 4♥. North leads ♠3. Who has the ace?
Intermediate and advanced players know the rule ‘do not lead away from an ace to a trump contract’.
This means that the player who has made the opening lead to your trump contract will not hold the ace in the suit led. If you think north is an experienced player then you should assume north has not led away from the ace.
You should be aware that the defender playing after the dummy is likely to play the ace on the card you choose to play from the dummy.
So south should have the ace.
Maybe north has the queen so if you play ♠6 from east, south will need to play the ace to win the trick. You can then win the king on the second round of spades.
Many beginners just lead out their aces so if north is a beginner they probably don’t have the ace as they would have led it. Once again, play low from east and hope south plays the ace.
However, if north is a novice, north may well have led away from the ace. Some inexperienced players lead ‘fourth highest of their longest and strongest’ to every contract so north could have led a spade when holding the ace.
If north has led away from the ace, you will need to play east’s king on the first trick to make the king. If you play low, south might win ♠Q and lead a second spade for north to win ♠A. Your ♠K is lost.
In other words, when deciding which opponent may have the ace, you need to consider the experience of the opponent who has led.
An advantage of playing online is that you can click on an opponent’s BBO name to see their level of experience!
© 2022 John Roberts