One of the common errors on defense is the play by third hand (partner of the leader) when dummy has an honor in the suit led. This exercise will help you determine when to finesse against dummy’s honor, and when to ignore it and play high.
One solution to the problem is to analyze every possible layout of the missing honors before you play. An expert might do this by drawing from past experience, but for the great majority of players it would take too long. A long huddle would also help declarer by revealing your problem, and it could be considered unethical since the information is available to partner.
Fortunately, there is an easier way. I have invented a few rules for this situation that work extremely well (exceptions are rare). Generally, the rules apply to all contracts, whether in notrump or a suit.
If your honor is one step above an honor in dummy, finesse if you have the eight or better.
If your honor is two steps above an honor in dummy, finesse if you have the nine or better.
Else play your highest card.
For example, assume you are East and your partner leads the two:
Your king is two steps above the jack, so you should finesse the nine when dummy plays low. If you had K-8-3, you should play the king.
Use my rules to find the right play for each of the following problems. Assume the contract is 3 NT.
Your play as East?
© 1994 Richard Pavlicek