There are many situations where the declarer has to 'take a view' on the second round of a suit. In this area both sides have opportunities for clever play.

You may remember reading about this deal from a past Sunday Times tournament.

As at most tables, Andrew Robson played 3NT from the South side. Dummy's ten of spades held the first trick and a diamond was won by the king. South ran the nine of clubs to East's ten, won the third round of spades, then led another club, on which West played low. Taking the view that if East had held the jack and ten he might have played the jack on the first round, Robson went up with the ace. Now he had nine tricks.

As Patrick Jourdain pointed out, West should have inserted the jack on the second round. Then South would probably have finessed the queen. There is a further interesting point. If West, a knowledgeable player, follows with the two and three, what conclusion should you draw? Presumably that he began with K32, not J32.

There are a few situations where the unnecessarily high card is absolutely necessary to give declarer the chance of going wrong. The first of these two is better known than the second.

(1)                       Dummy

                         ♠   8 3

Partner                                         You

♠  K Q                               ♠  10 6 2

                   Declarer

                   ♠  A J 9 7 5 4

(2)                      Dummy

     ♠   Q10864

Partner                                You

♠   J72                                          ♠  K95    

                      Declarer  

                        ♠  A 3

In (1), after the eight has run to partner's king (or queen), East must not fail to insert the ten when the next card is led from dummy. Otherwise South, needing five tricks, will play the ace; it will be his only chance to make the remainder.

In (2) declarer leads low to the ace. Would it have occurred to you as East that you must play the nine? This will encourage South to play the queen from dummy on the next round, because of the chance of dropping a doubleton jack-nine (to find East with king-nine won't help).

The common factor in these deceptive plays is that it is generally right for a defender to play a card that cannot conceivably take a trick but may mislead the declarer.

Now let's look at one or two situations where the declarer has the chance to draw a particular inference. Consider this frequent position:

Dummy

♠  1053

Declarer

♠  AK642

You play off the ace and king. East follows with two low cards, West with a low card and the queen. Who has the jack? Probably East, because with QJx West might equally have played the jack on the second round. Similarly:

Dummy

♠  7 6 4

Declarer

♠  A Q 8 5 2

On a low card from dummy East plays the ten and the queen holds. The ace follows and East drops the king. Who has the jack? More likely

West, as with KJ10 East might have played the jack on the first round. You always assume that a player did not have a choice.

My BOLS bridge tip is:

As a defender, consider playing an unnecessarily high card on the second
round of a suit; as declarer if you need to place a missing honour assume
the defenders had no choice about which honour to play.

Think along these lines whenever you make a decision on the second round of a suit. In time you will gain the reputation of being a  good guesser. Or a good looker.